Baked Shells with Winter Squash

Directions

1. 1
   Preheat the oven to 400F.
2. 2
   Butter a 9-by-13-inch baking dish.
3. 3
   Heat 3 tablespoons of the oil in a large skillet over medium-low heat.
4. 4
   Add the onions; season with salt and pepper.
5. 5
   Cover; cook until the onions are soft and release their liquid, about 15 minutes.
6. 6
   Uncover; raise the heat to medium.
7. 7
   Cook, stirring, until the onions are browned, 20 to 25 minutes.
8. 8
   Stir in 1 teaspoon of the rosemary.
9. 9
   Meanwhile, cook the pasta in a large pot of boiling salted water for 2 minutes less than the package instructions suggest.
10. 10
    Drain, reserving 1 1/2 cups of the cooking water.
11. 11
    Return the pasta to the pot.
12. 12
    Stir squash and reserved pasta water into the onions; simmer for 2 minutes.
13. 13
    Toss the squash mixture and 1/2 cup of the Parmesan with the pasta.
14. 14
    Transfer to the prepared dish.
15. 15
    Combine the bread cubes with the remaining Parmesan, rosemary, and oil; season with salt and pepper.
16. 16
    Top the pasta with the bread cubes; bake until golden brown, 10 to 15 minutes.
17. 17
    Roast whole winter squash on a rimmed baking sheet, turning occasionally, until very tender when pierced with a knife, about 1 hour, depending on the size of the squash.
18. 18
    When cool enough to handle, halve the squash lengthwise and scrape the flesh into a food processor (discard the skin and seeds).
19. 19
    Puree until smooth.
20. 20
    You will need 2 cups (from about 3/4 pound squash).