7 Leftover Upgrades Worth Raiding the Fridge For

You wouldn't flush your hard-earned money down the drain, so why let last night's leftovers go to waste? Our collection of ideas and recipes will help you creatively -- and deliciously -- reinvent your food.

1. Make a Vinaigrette from Mustard

When there's just a tiny bit of mustard left in the jar, don't throw it out. Instead, toss in a few ingredients, and shake a tangy Dijon vinaigrette right in the container. A crushed garlic clove, some chopped fresh herbs -- tarragon, for instance -- and minced shallot will add the right flavor. Pour in balsamic vinegar, season with salt and pepper, then close the lid and shake. Add olive oil (3 parts oil to 1 part vinegar); shake again to emulsify the dressing, and then drizzle over your favorite salad. With a tightly sealed lid, the dressing will keep in the refrigerator for up to one week.

2. Make Pancakes and Soup from Mashed Potatoes

Leftover, cold mashed spuds might as well be labeled, "Now what?" But these tasty recipes for using them up may even convince you to make extra.

Mashed-Potato Pancakes
Potato Croquettes
Potato-Leek Soup

Related: Quick, One-Pot Meal Ideas To Feed the Whole Family

3. Make Fried Rice from Leftover Rice

Use up leftover rice, plus whatever vegetables and protein you have on hand, in a delicious one-dish meal.

Fried Rice with Ham

2 tablespoons vegetable oil
Coarse salt
3 large eggs, lightly beaten with 2 teaspoons water
4 scallions, thinly sliced
4 garlic cloves, minced
5 ounces ham, thinly sliced and cut into strips
3 tablespoons rice vinegar
1 1/2 cups frozen peas, thawed
4 cups cooked rice

1. In a large nonstick skillet, heat 1 tablespoon oil over medium-low heat; swirl to coat pan. In a small bowl, lightly beat together eggs, 2 teaspoons water, and 1/4 teaspoon salt. Pour into pan; cook, pulling in egg from edge of pan, until set, about 2 minutes. Transfer to a plate; when cool enough to handle, cut into strips.

2. In pan, heat remaining tablespoon oil over medium heat. Add scallions and garlic; cook until fragrant, about 1 minute. Add ham and rice; season with salt. Cook, stirring often, until very hot, about 5 minutes.

3. Add vinegar, peas, and eggs; cook until very hot, about 2 minutes.

4. Make Quesadillas with Leftover Meat

Quesadillas are a delicious way to use leftover cooked meat. Keep tortillas, cheese, and jarred salsa on hand. Sandwich the ingredients between the tortillas, and cook in a skillet with a bit of oil for a few minutes per side.

Related: 15 Kitchen Shortcuts That Will Change the Way You Cook

5. Make Stock from Turkey Bones

Turn leftover chicken or turkey bones into a flavorful stock to use in future meals.

Easy Turkey Stock

5 pounds leftover turkey bones (with some meat still attached), broken into large sections if necessary
1 pound yellow onions, skins on, halved or quartered depending on size
1/2 pound carrots, cut into 4-inch lengths
1/2 pound celery stalks, cut into 4-inch lengths
1/2 teaspoon whole black peppercorns
8 sprigs parsley

1. In a 3-gallon stockpot, combine all ingredients and fill with enough cold water to cover ingredients by 3 inches when submerged (about 6 quarts).

2. Bring to a rapid simmer over high (do not boil); reduce heat until bubbles barely break the surface. Simmer until flavorful, about 2 hours, skimming stock with a ladle every 30 minutes.

3. Strain stock through a fine-mesh sieve. Discard vegetables. Remove meat from bones and save for another use; discard bones. Let stock cool completely before refrigerating.

6. Make Syrup with Leftover Herbs

Don't let an abundance of herbs go to waste. Pluck several types of sprigs -- we chose basil, mint, and thyme -- and use them to flavor a basic sugar syrup. Mix the concoction with ice and sparkling water, then garnish the drinks with additional sprigs. You can also freeze the infused syrup in ice cube trays and enjoy it for up to a month.

Herbal Sodas

1/2 cups sugar
3/4 ounce fresh herbs, such as basil, lemon verbena, mint, tarragon, or thyme
1 teaspoon freshly squeezed lemon juice
Ice, for serving
Sparkling water or club soda, for serving

1. Put sugar and 1 cup water into a medium saucepan over medium heat. Bring to a simmer, stirring until the sugar has dissolved. Remove from heat; add herbs. Cover; let cool completely.

2. Pour syrup through a fine sieve into a small bowl; discard herbs. Stir in lemon juice. Refrigerate at least 30 minutes.

3. Fill glasses with ice. Add 2 to 4 tablespoons syrup; top with sparkling water or club soda, and stir.

7. Make Sauce from Leftover Wine

Don't pour leftover wine from your dinner party down the drain! Instead, pour the remainder into a resealable bag and freeze it. Next time you need to deglaze a pan after frying or sauteeing meat, just add a 1/2 cup of your reserved wine and a bit of butter.

More from Martha Stewart:
10 New Ways to Use Leftover Bacon Grease
35 Beyond Delicious No-Bake Dessert Recipes
Healthy Afternoon Snacks You'll Dream About All Day
15 New Ideas for a Healthy, Delicious Breakfast