Mac and Cheese with Cauliflower

Macaroni and cheese with cauliflower (Dave and I LOVE this one)
hands-on time: 15 minutes total time: 45 minutes serves 6
RealSimple, Feb 2009
Nutrition per serving: 537 calories; 23g fat (9g saturated fat); 51mg cholesterol; 692mg sodium; 24g protein; 63g carbohydrates; 8g fiber.

Cooking with extra-sharp Cheddar lets you use less cheese without giving up flavor. Tender cauliflower adds fiber and vitamin C. From
12 ounces multigrain elbow macaroni
1 head cauliflower, roughly chopped
4 slices multigrain bread, torn
1/2 cup fresh flat-leaf parsley, chopped
3 tablespoons Olive oil
Kosher salt and black pepper
1 onion, finely chopped
1.5 cups grated extra-sharp Cheddar
(6 ounces)1.5 cups reduced-fat sour cream
1/2 cup 1 percent milk
1 tablespoon Dijon mustard

~Heat oven to 400 degrees F. Cook the pasta according to the package directions, adding the cauliflower during the last 3 minutes of cooking time; drain.
~Meanwhile, pulse the bread in a food processor until coarse crumbs form. Add the parsley, 2 tablespoons of the oil, and 1/4 teaspoon each salt and pepper and pulse to combine; set aside.
~Return the pasta pot to medium heat and add the remaining tablespoon of oil. Add the onion, 3/4 teaspoon salt, and 1/2 teaspoon pepper and cook, stirring occasionally, just until soft, 5 to 7 minutes. Mix in the pasta, cauliflower, cheese, sour cream, milk, and mustard.
~Transfer to a shallow 3-quart baking dish, sprinkle with the bread crumbs, and bake until golden brown, 12 to 15 minutes.