Cheddar Broccoli Pasta Bake

COMMENTS:
This recipe is missing something... BUT, my kids snarfed this down like it was a dessert and it got them to eat broccoli so it is now a keeper. Let me know if you figure out what is missing to make this just as delicious for the parents! :) This is also a good make ahead meal - just add an extra ten minutes or so to baking time.

INGREDIENTS:
16 oz. pasta (I used mini shells)
1 cup milk
1 can cream of chicken soup
1 teaspoon mustard (prepared)
2 teaspoons mayonnaise
1 tablespoon olive oil
1 small onion, chopped
1 1/2 cups cheddar cheese, shredded and divided
10 oz frozen broccoli, chopped

DIRECTIONS:
Preheat oven to 350 degrees.
Boil water to cook pasta for 5 minutes; add broccoli and boil an additional two minutes.
Spray 2-quart casserole dish with cooking spray.
In a medium bowl, combine milk, soup, mustard, and mayo; set aside.
Heat olive oil in saucepan over medium heat. Add onion; cook and stir for two to three minutes. Add milk mixture and bring to boil, stirring constantly. Boil one minute. Remove from heat, stir in 1 cup of cheese until smooth. Blend in drained broccoli and pasta. Pour mixture into prepared casserole dish. Top with remaining cheese. Bake for 20 minutes or until hot and bubbly.