This came from my friend Eve Savage's Mom:
Macaroni and Cheese
1 ½ cup elbow macaroni
1 tablespoon olive oil
1 tablespoon all-purpose flour
1/2 cup nonfat milk (skim)
1/2 cup butternut squash or cauliflower, puree
8 ounces cheddar cheese, shredded
4 ounces cream cheese
1/2 teaspoon salt
1/8 teaspoon paprika
1/8 teaspoon pepper
Bring a large pot of salted water to a boil, add the macaroni and cook according to package directions until al dente. Drain in a colander.
While the macaroni is cooking, coat a large saucepan with cooking spray and heat over medium heat.
Add the oil, then the flour, and cook, stirring constantly, until the mixture resembles a thick paste but has not browned (1-2 minutes).
Add the milk and cook, stirring every now and then, until the mixture begins to thicken (3 to 4 minutes).
Add the vegetable puree, cheddar, cream cheese and seasonings and stir until the cheese is melted and the sauce is smooth. Stir in the macaroni and serve warm.