Name: Unstuffed Shells with Butternut Squash and Leeks
Total time: 1 h 15 min
Ingredients: 8 ounces (1 cup) whole-milk ricotta cheese; 2 ounces Parmesan cheese , grated (1 cup); 1 teaspoon grated lemon zest; Salt and pepper; 1 tablespoon extra-virgin olive oil; 1½ pounds butternut squash , peeled, seeded, and cut into ½-inch pieces (5 cups); 1 pound leeks , white and light green parts only, halved lengthwise, sliced thin, and washed thoroughly; 2 garlic cloves , minced; Pinch cayenne pepper; ¼ cup dry white wine; 4 cups water; 1 cup heavy cream; 12 ounces jumbo pasta shells; 2 tablespoons chopped fresh basil

Why This Recipe Works

We quickly found the right ratio of liquid to shells to ensure perfectly cooked noodles, but finding the ideal amount of vegetables proved trickier. Cooking butternut squash and leeks in a creamy sauce promised a hearty vegetarian meal, but if we used too much of either vegetable, the skillet was prone to overflowing; too little and the servings looked meager. We settled on 1½ pounds of squash and 1 pound of leeks. Cooking them briefly before adding the pasta and liquid deepened their flavors and ensured that the pasta and squash would finish cooking at the same time. Instead of stuffing the shells, we sprinkled a little Parmesan cheese and dolloped a rich lemon-ricotta mixture over everything before sliding the skillet back in the oven to brown and melt the cheesy toppings.

Before You Begin

You can substitute large or medium shells, ziti, farfalle, campanelle, or orecchiette for the jumbo shells here. The skillet will be very full when you add the shells in step 3 (stir gently to start), but will become more manageable as the liquid evaporates and the shells become more malleable. You will need a 12-inch ovensafe nonstick skillet for this recipe.

Instructions

Adjust oven rack to middle position and heat oven to 375 degrees. Combine ricotta, ½ cup Parmesan, lemon zest, ¼ teaspoon salt, and ¼ teaspoon pepper in bowl; cover and refrigerate until needed.

Heat oil in 12-inch ovensafe nonstick skillet over medium heat until shimmering. Add squash, leeks, and ½ teaspoon salt and cook until leeks are softened, about 5 minutes. Stir in garlic and cayenne and cook until fragrant, about 30 seconds. Add wine and cook until almost completely evaporated, about 1 minute.

Stir in water and cream, then add pasta. Increase heat to medium-high and cook at vigorous simmer, stirring gently and often, until pasta is tender and liquid has thickened, about 15 minutes.

Season with salt and pepper to taste. Sprinkle remaining ½ cup Parmesan over top, then dollop evenly with ricotta mixture. Transfer skillet to oven and bake until Parmesan is melted and spotty brown, about 5 minutes. Remove skillet from oven (skillet handle will be hot). Let cool for 10 minutes, then sprinkle with basil and serve.