Step 1

Preheat the oven to 350 degrees F.

Step 2

Toast the pasta: In a large oven-safe saucepan, heat the oil over medium heat. Break the pasta (!) into smaller pieces, about 2 inches long, and add to the oil. Season with salt. Stir with a wooden spoon so the pasta doesn’t stick to the bottom, tossing to coat with the oil. Toast the pasta, stirring often, until golden brown, 2 to 3 minutes.

Step 3

Build the sauce: In a blender, purée the onion, garlic, tomatoes and 3 1/2 cups chicken stock until smooth.

Step 4

Finish the pasta: Add the red pepper flakes and butternut squash to the pan. Pour the tomato mixture from the blender over the pasta and stir to combine. Bring to a simmer, then place the saucepan in the center of the oven. Bake until it thickens to a stew-like consistency and the pasta is cooked, 12 to 15 minutes. Add the remaining 1/2 cup of stock if too thick. Stir in the basil and sprinkle with some cheese.

Step 5

Serve: Ladle the soup into bowls. Squeeze the lime over the pasta.