Macaroni and Cheese with Butternut Squash

Ingredients in this Recipe

1 1/2 cups nonfat milk
1 cup homemade or low sodium canned chicken stock, skimmed of fat
1 pound elbow macaroni
1 small butternut squash (about 1 pound) , peeled, seeded, and cut into 1 inch cubes (about 3 cups)
1 teaspoon olive oil
1/2 cup part skim ricotta cheese
2 tablespoons fine breadcrumbs
3/4 teaspoon coarse salt
4 ounces extra sharp cheddar cheese, finely grated (about 1 cup)
4 tablespoons Parmesan cheese, finely grated (1 ounce)
Freshly ground black pepper
Olive oil cooking spray
Pinch of freshly grated nutmeg