We love these vegetable stuffed shells! If you have one, cook the vegetables in a wide oven-safe skillet. Then, bake the shells in the same pan. If you do not have an oven-safe skillet, bake the shells in a baking dish.
This filling is enough for about 16 shells. We recommend adding a couple of extra shells to the water since you might find that one or more shells tear while cooking.
18 jumbo pasta shells
4 ounces mushrooms, thinly sliced, about 2 cups sliced
1 medium bell pepper, chopped
5 ounces spinach leaves, about 4 cups packed
3 garlic cloves, 1 tablespoon minced
2 cups whole milk ricotta cheese
3 ounces finely grated parmesan cheese, about 1 cup
1/4 cup fresh basil leaves, chopped or substitute 1 teaspoon dried
1/2 teaspoon dried oregano
3 cups marinara sauce, try our homemade marinara sauce
2 ounces shredded mozzarella cheese, about 1/2 cup
Fine sea salt and fresh ground black pepper
Preheat the oven to 400°F (204°C).
Bring a large pot of salted water to a boil. Add shells and cook, stirring occasionally, until very al dente, about 9 minutes. Drain. Run under cold water to stop the cooking, then drain again.
Meanwhile, heat the oil in a wide oven-safe skillet over medium heat. Add mushrooms and spread into one layer. Cook, without moving, until browned on one side, 3 to 5 minutes. Stir, then add the chopped bell pepper. Cook, stirring occasionally until the peppers are starting to soften, about 2 minutes. If you do not have an oven-safe skillet, a regular skillet will work fine, you will just need to bake the shells in a baking dish instead of the skillet later on.
Pile the spinach leaves into the pan and add the garlic and a generous pinch of salt. Wait about 30 seconds or until the bottom layer of leaves has started to wilt, and then toss the leaves around the pan. As the spinach cooks, keep tossing so that all the leaves have a chance to hit the bottom of the skillet. When the spinach looks bright green and is mostly wilted, remove the pan from the heat and allow the vegetables to cool off for a minute or two.
Combine the ricotta cheese, parmesan cheese, basil, oregano, 1/2 teaspoon of salt, and 1/2 teaspoon of pepper in a medium bowl. Stir in the vegetables and then taste the mixture. Adjust as needed with more salt or pepper.
Place the oven-safe skillet over low heat. Pour in the marinara sauce and heat until barely simmering. Turn the heat off. If you do not have an oven-safe skillet, transfer the warmed marinara sauce to a large baking dish. (If you have an oven-safe skillet, you can use it to bake the shells.)
Spoon 2 tablespoons of the cheese mixture into each cooked shell, then nestle the filled shell down into the warmed marinara sauce. If you have any cheese mixture left, divide it between the shells or enjoy it with any leftover shells.
Bake, uncovered until the shells are heated all the way through and the cheese is melted on top, about 20 minutes. Remove from the oven and let sit 5 minutes before serving.