Macaroni and Cheese With Cauliflower

Not your everyday mac-n-cheese!
Thanks again Real Simple.
Even the kids love this one. :)

Ingredients:

• 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 1/2 cups grated extra-sharp Cheddar (6 ounces)
• 1 1/2 cups reduced-fat sour cream
• 1/2 cup 1 percent milk
• 1 tablespoon Dijon mustard

Directions:

1. Heat oven to 400° F. Cook the pasta according to the package directions, adding the cauliflower during the last 3 minutes of cooking time; drain.
2. 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.
3. 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.
4. Transfer to a shallow 3-quart baking dish, sprinkle with the bread crumbs, and bake until golden brown, 12 to 15 minutes.