Spring cleaning is not just for closets and the garage. Take a look inside your refrigerator.

If its anything like mine, there’s an assortment of plastic containers, jars and amorphously shaped foil blobs that haven’t seen daylight in some time.

But before you pull up the trash bin consider putting some mystery items to work.

Instead of just reheating yesterday’s meal, why not make a salad with strips of roast chicken or porkchop? And turn those green beans into an all-American green bean casserole.

We had some ground beef, ground turkey and mashed potatoes sitting around, so we made an English favorite, shepherd’s pie. It’s a great way of stretching — and dressing up — a small amount of meat.

Shepherd’s pie is a saute of meat and vegetables topped with potatoes, usually of the mashed variety.

Sounds a lot more yummy than dry, reheated roast or hamburgers.

We used a combination of ground turkey and ground beef, though lamb is most traditional. If you’re using leftovers, just heat them up in olive oil before adding diced vegetables.

If you’re starting from raw meat, you’ll want to brown it in a skillet. But be sure not to turn the meat too much, as this prevents adequate browning (important for taste). Instead, put it in the pan and cut your vegetables while it cooks, turning only every few minutes.

Second-day mashed potatoes have never been a staple on my menu, but reheating them in a saute pan on medium-low with butter and milk or cream will sufficiently revive them. Plus, the dish is finished in the oven, giving the potatoes a chance to brown and develop a firmer texture.

No matter how bad you think your meat mixture looks, don’t worry. You’re going to top it with potatoes, and there’s room for some creativity here. All you need is a pastry bag.

You can use a cake decorating tip to make scalloped swirls, or you could just pipe out tube shapes. Cut the opening in the bag if you want bigger tubes.

Shepherd’s Pie

Start to finish: 11⁄2 hours (1 hour active)

Servings: 6

2 tablespoons olive oil

11⁄2 pounds lean ground beef or turkey

1 cup minced onion

1⁄2 cup minced celery

1 cup diced carrot

1 cup peas (thawed if frozen)

1 cup green beans, trimmed and diced

11⁄2 cups tomato sauce

3 tablespoons tomato paste

1⁄2 cup dry red wine (optional)

Salt, to taste

Freshly ground black pepper, to taste

2 tablespoons chopped flat-leaf parsley

1 tablespoon chopped fresh oregano or thyme

3 cups mashed potatoes

Preheat the oven to 350 degrees.

In a large skillet over medium, heat the oil until it shimmers. Crumble the ground beef or turkey into the pan and saute, stirring occasionally until the meat no longer looks raw, about 5 minutes.

Add the onion, celery, carrot, peas and green beans. Reduce the heat to low and cook, stirring frequently, until the onion is translucent and all the vegetables are hot, 8 to 10 minutes.

Add the tomato sauce, tomato paste and wine, if using, and bring to a simmer.

Season with salt and pepper. Simmer, stirring from time to time, until the sauce has thickened, another 10 to 12 minutes. Remove the skillet from the heat and stir in the parsley and oregano or thyme.

Transfer the meat and vegetable mixture to a 21⁄2-quart casserole. Spoon or pipe the potatoes into an even layer that completely covers the meat. Bake until the potatoes are very hot and have a light golden crust, about 30 minutes. Serve immediately.

(Adapted from The Culinary Institute of America’s “One Dish Meals,” Lebhar-Friedman Books, 2006)