Why more cooks -- and gardeners -- should embrace sorrel, an underrated lemony leaf

May 19—In an entry on sorrel in her encyclopedia of "Uncommon Fruits & Vegetables," food writer Elizabeth Schneider noted that "Americans seem to have an on-again off-again affair with the sharply acid green leaves to which the French have been devoted as long as there has been a France."

These days, that relationship is mostly "off," at least as far as I can tell. And while it may be overly ambitious of me, I hope to change that, if not in the whole of the country, then at least in my own corner of Maine. Why? Because cultivated garden sorrel — an early spring green in Maine, here at a time that little else local is around — is easy to cook with and a pleasure to eat.

If my own enthusiasm isn't persuasive, nor sorrel's durable French culinary pedigree, perhaps you'll be swayed by Kyle Robinson, chef and co-owner of Chez Rosa in Kennebunkport.

"I personally love it. I have no idea why we (Americans) don't love it," he said in a telephone interview. "It's phenomenal. It adds this pop of acidity, this pop of flavor. It just really brightens up dishes. I'm not quite sure why it hasn't gained more popularity, more traction in cuisine in the United States."

Sorrel comes in dozens of varieties, according to Alan Davidson in "The Penguin Companion to Food," which "have been eaten as green vegetables since ancient times." In his own food dictionary, "Food," Waverly Root writes that the British were big fans way back in the time of Henry VIII. He also notes that, in 1895, "20 million kilograms (44 million pounds) of sorrel leaves were delivered to the Paris markets."

The French traditionally use sorrel in salads, soups, sauces and eggs. They pair it with fatty fish and veal. The Salmon with Sorrel Sauce dish developed in the early 1970s by the Troisgras brothers at their eponymous three-Michelin-star restaurant was legendary and is credited with kicking off France's nouvelle cuisine revolution. Puckery, lemony sorrel leaves add balance to classic French dishes laden with cheese, butter and heavy cream.

Sorrel soup is a rite of spring in France, according to John Holm, chef and co-owner of Maine Street Bistro in Brunswick. And while I don't have a drop of French blood, I make a version every spring myself, supplementing the sorrel with carrots, potatoes, rice and, inevitably, cream. Messing about with sorrel in my own kitchen, I've successfully used it in pesto, risotto, quiche and even smoothies, the last as you might add spinach — for a nutritional boost.

Culinary experts say the leaf is also enjoyed in Norway, Lapland, Hungary, China, Japan and India (which reminded me that I've previously enjoyed Madhur Jaffrey's Toovar Dal with Spinach and Sorrel, from "Vegetarian India." Note to self: Make again.)

Come fall, Robinson likes to pair sorrel with apples. "It can be pretty universal," he replied when asked what other foods and flavors suit sorrel. "If you are just looking to add a little brightness to something that you're making, it can fit in a lot of different places. It's spring right now: It'd be pretty great on an asparagus salad. If you were doing something with peas, it'd be super great there. Anything you might put lemon with, try it with sorrel."

SORREL EMERGENCY

But before you can cook with it, you need to procure it, and that isn't easy. Chefs say they get it from their wholesale suppliers, which will not help you, alas. I have a patch in my garden, but when I worried, last-minute, that it wouldn't supply enough to let me test recipes for this article — a huge pile of sorrel will reduce, dramatically and quickly, almost the moment you apply heat — I drove to Whole Foods, my neighborhood Rosemont Market and Hannaford in search of it, and I called up Portland Press Herald garden columnist Tom Atwell as well as Jordan's Farm farmstand in Cape Elizabeth. No dice, no dice, no dice, no dice, no dice — and no sorrel.

"I am going to ask you a question you are not going to like," my partner said at this juncture. We've been together almost 15 years; I imagined the worst. How, he asked, are people supposed to get sorrel if you, the food editor, can't even find it?

That's when I posted a frantic note desperately seeking sorrel on the neighborhood social networking site Nextdoor. I got 10 responses, including this one: "Not too cultured, what the hell is sorrel and why is it an emergency?" That made me laugh, but Maggy Wolf's generous response made me sigh with relief. I've got some, she messaged me. Would you like it?

Would I ever. Within an hour, she'd sent me three texts with pictures, she'd harvested the sorrel and she'd generously left it in a brown shopping bag (a Rose Foods bag, no less; Maggy and I are apparently simpatico) by her front door for me. "I hope you are not too squeamish about slugs and snails," one of those texts said, the "snails" represented by an emoji.

I bought my own plants (Latin name Rumex acetosa) from Goranson Farm in Dresden about six years ago. "We have been selling sorrel at markets for years," Jan Goranson emailed me when I asked her about the herb. She has few customers for it, she continued, "but those who love it really LOVE it."

Which gives you three options for finding sorrel:

1) Try your local farmers market. (Dandelion Spring Farm, in Bowdoinham, also sells it at local markets. "We have it regularly through the spring and in fall," Beth Schiller wrote in an email. "Sometimes we bring it to market through the summer, depending on interest.")

2) Find a friend who grows it and is willing to supply you.

3) Grow it yourself.

Believe me, if I can grow it, anybody can. The plant is a perennial that not only grows happily and independently but, if cut back in August, will give me a fall crop, too. While researching this article, I learned it's a cousin to rhubarb. Given that both are bracingly sour, maybe that shouldn't have surprised me.

Come to think of it, you've got four options for getting your hands on sorrel, though this last one may take time: Ask your local farmer for sorrel. Chances are, they are looking for a new niche crop. If enough of us express interest, sorrel could one day be the new groundcherry or garlic scape.

TASTE TEST

The sensible cook may want to taste sorrel for herself before committing any precious garden space. You can often find it on the menu at Maine Street Bistro, where lately Holm and his business partner, Brendon Franklin, have been using it in a Brittany-style fish stew. The sorrel is added, as is often the case, at the end of cooking, after the pot is taken off the heat. "The residual heat cooks it," Holm said. "It's like giving it a fresh herb shot right at the end of cooking."

Robinson prefers sorrel uncooked, and here's why: The minute you apply heat, sorrel turns a drab brown-green. "I prefer to use it more on the raw side of things. It's really great raw with a raw seafood or a raw scallop dish, in salads," he said. "When people eat it they are like, 'Whoa! What was that?!' It's hard for me to look at color of sorrel when it's cooked. It turns that really dull, unappetizing-looking green."

Personally, I am Switzerland in this debate. I like sorrel in a box, with a fox, both jauntily colored and army green. But if you do eat it raw, cut the sorrel into ribbons as it is strong stuff. Another characteristic of sorrel that may catch you up short if you haven't cooked with it before: The leaf "melts" — or, as the French put it, "faire fondre" — when it is heated. I've read Americans describe it less charitably as turning to "mush." Don't fret. You're not doing anything wrong.

Amanda Hesser included several recipes that call for sorrel in her book "The Cook and the Gardener," a chronicle of the year she spent in France at the renowned cooking school La Varenne. Alongside her recipe for sorrel soup, she wrote, "For most Americans sorrel has a taste that is yet to be acquired and may never be, as with snails and offal."

I am an admirer of Hesser, who, after a career as a very young food reporter and then food editor at the New York Times, went on to found the wildly successful Food 52 website. Still, I must register a protest: I get why offal or snails can be hard for us Americans to stomach. But sorrel? The Sour Patch version of spinach (minus the sugar)?

Mainers, let's prove her wrong. Let's acquire this invigorating taste.

CREAM OF LENTIL-SORREL SOUP

The recipe is from Deborah Madison's "Vegetable Soups." I used water as the base of the soup and still found it nicely flavored. The sorrel brightens the usually earthy lentil soup.

1 cup brown lentils or pardinos, soaked for at least 1 hour

2 to 4 tablespoons olive oil

1 onion, sliced

2 celery ribs, sliced

1 carrot, sliced

2 bay leaves

Handful of parsley, chopped (about 1/2 cup)

3 garlic cloves, chopped

6 to 8 cups water or vegetable or chicken stock

Salt and pepper

2 packed cups sorrel leaves (about 3 1/2 ounces)

1/2 cup cream or 1 cup half-and-half

Toast for croutons

Heat the oil in a soup pot and add the vegetables, bay leaves, parsley and garlic. Give a stir, then cook over medium-high heat, stirring now and then for 5 minutes. Add the lentils, water or stock and 1 1/2 teaspoons salt. Bring to a boil, then simmer, covered, until the lentils are squishy-soft, as long as an hour.

Remove the bay leaves. Add the sorrel and allow it to melt into the hot liquid, about 3 minutes, then puree the soup in a blender on high speed. Pass everything through the finest holes of a food mill if you want a smoother, more elegant soup. Stir in the cream. Taste for salt and season with pepper.

Break the toast into small pieces or cut into cubes and add the croutons to the soup. You can garnish with a few ribbons of raw sorrel if you like.

SORREL-POTATO GALETTE

You'll need a cast-iron skillet to make this dish, which is from Amanda Hesser's "The Cook and The Gardener." A mandoline is also useful. Hesser describes it as a simple recipe in which the devil is in the details: "... it is careful controlling of the heat on the stove that determines its success or failure," she writes. The galette is a textbook example of a very rich dish brightened and lightened by sorrel. It best suits a cool spring or fall evening, when sorrel is available.

1 1/2 pounds small, equal-sized waxy potatoes (such as yellow fingerlings), peeled

5 tablespoons butter

Kosher salt

Freshly ground black pepper

2 handfuls sorrel, ribs removed, leaves washed

1/4 cup grated Gruyere cheese

3/4 cup freshly grated Parmigiano-Reggiano cheese

Heat the oven to 350 F. Slice the potatoes into 1/8-inch rounds with a knife or mandoline.

Heat 3 tablespoons of the butter in an 8-inch iron skillet over medium heat until foaming, then reduce the heat to low while you layer the ingredients in the pan. You want to color the potatoes at the bottom of the skillet slowly and evenly. Lay a slice of potato in the center, then layer more potatoes in overlapping concentric circles to fill the base of the pan. Arrange a single overlapping layer on the sides of the pan. Sprinkle the potatoes with salt and pepper.

Fill the pan with all but one-quarter of the remaining potatoes. Place them evenly so the galette will not be lopsided when it's turned out.

Season again with salt and pepper and dot with 1 tablespoon butter. Lay the sorrel leaves over the potatoes to cover. The leaves will seem like a lot, but don't worry, they will melt to a thin layer as the galette bakes. Top with the grated cheese and more pepper. Top with the remaining potatoes. Don't be afraid to stuff the pan as the potatoes will also contract as they cook.

Dot with the remaining 1 tablespoon butter. Increase the heat to medium. Saute until the potatoes on the sides of the pan begin to cook, 5 to 7 minutes. Cover the skillet tightly with a lid or aluminum foil and place in the heated oven. Bake 30 to 35 minutes until the potatoes are tender all the way through when poked with a fork. Remove from the oven.

Now here's the tricky bit: Run a thin, flexible spatula around the sides and outer base of the skillet to loosen any stuck potatoes. Invert onto a serving plate in one swift motion (watching out for dripping butter). Carefully lift off the skillet, gently prodding any potatoes that have attached themselves to it and patching them where possible. The galette should be well-browned and shiny. Serve in wedges.

Here's how Hesser reassuringly finished her recipe instructions.:"If there are any major flaws, such as a gaping hole, I always remind myself of what Julia Child says, 'That's what parsley is for.' "

SORREL-BUTTERMILK PANNA COTTA

This imaginative recipe comes from Ian Knauer's "The Farm: Rustic Recipes for a Year of Incredible Food." He suggests you top the panna cotta with whipped cream; I find it rich enough as is so prefer it with fresh berries. The dessert is not too sweet, easy to make but impressive to eaters, a great spring color, and a little mysterious — in a good way — because you can't quite identify the flavor.

2 1/4 teaspoons unflavored gelatin

2 tablespoons cold water

6 cups sorrel (3 1/2 ounces)

1 1/2 cups buttermilk

1 1/2 cups heavy cream

2/3 cup sugar

Pinch kosher salt

Lightly oil eight 3- to 4-ounce ramekins.

Sprinkle the gelatin over the water in a small bowl and let it stand for 1 minute to soften.

Puree the sorrel with the buttermilk in a blender until it is very smooth, about 1 minute. Strain the buttermilk mixture through a fine-mesh sieve into a medium bowl, pressing on the solids. Compost the solids.

Heat the cream with the sugar and salt in a small, heavy saucepan over medium heat, stirring until the sugar has dissolved. Add the gelatin mixture and stir until dissolved. Pour the cream mixture into the buttermilk mixture and divide among the ramekins. Cool completely, then cover the ramekins and refrigerate the panna cottas until they are set, at least 4 hours. Serve with fresh berries.