Macaroni and Cheese with Cauliflower

This recipe is from Dish Delish and I loved it! The kids weren't thrilled, but they ate it (I used gluten-free noodles because I had a feeling I'd be the one eating most of it). I loved that it was full of cauliflower and still delicious!

Ingredients:
* 12 ounces multigrain elbow macaroni (I used gluten-free penne)
* 1 head cauliflower, roughly chopped
* 4 slices multigrain bread, torn (I skipped the topping)
* 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 (I used 2% cheese)
* 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.