This meal is by far my favorite pasta dish. It is very easy to put together and requires mostly ingredients that I always have on hand. Oh, and it tastes delicious too! I found this recipe over at Annie's Eats, I tweaked it a little by adding in a green bell pepper.
1 12-oz. package of jumbo pasta shells
1 tablespoon olive oil
1 cup yellow onion, finely chopped
1 pound Italian sausage
3 cloves garlic, minced
1 large egg, lightly beaten
1 15-oz. container ricotta cheese
10 oz. frozen chopped spinach, thawed and drained
1 green bell pepper, finely chopped
1 cup grated Parmesan cheese, divided
1 teaspoon dried basil
1/4 cup bread crumbs, substitute 6 club crackers
1/2 teaspoon salt
1/2 teaspoon pepper
1 28-oz. can chopped tomatoes with herbs, including the liquid
Bring a large pot of salted water to boil. Cook pasta shells according to package directions. Drain, rinse with cold water, and set aside.
Heat olive oil in a large skillet over medium-high heat. Add the onions and bell peppers and cook until softened, about 5 minutes. Add the sausage to the pan, breaking it up as it cooks. Cook until the sausage is completely cooked and no pink remains. Add the garlic and cook about 30 seconds. Remove from heat.
In a large mixing bowl, combine the egg, ricotta, spinach, 1/2 cup of the Parmesan, basil, bread crumbs, salt, and pepper. Stir together to combine. Add the cooked sausage mixture to the bowl and stir until evenly mixed.
Preheat the oven to 375 degrees F. Spread a thin layer (about half) of the chopped tomatoes in the baking dishes (either three 8x8" pans, or one 9x13" and one 8x8"). Stuff each shell with some of the cheese mixture, and arrange in the baking dishes, open side up. Spread the remaining tomatoes over the top of the pasta shells.
Cover the pans with foil and bake for 30 minutes, until hot and bubbling. Remove foil and sprinkle with remaining Parmesan cheese. Bake, uncovered, for 10 more minutes.