Creamy Chicken and Broccoli Casserole

1 (12-ounce) package steam-in-bag broccoli florets

1 tablespoon canola oil

1 cup prechopped onion

2 (8-ounce) packages presliced mushrooms

3 tablespoons all-purpose flour

1 1/2 cups fat-free milk

12 ounces chopped skinless, boneless rotisserie chicken breast (about 3 cups)

1/2 cup plain fat-free Greek yogurt

1/4 cup canola mayonnaise

1/2 teaspoon freshly ground black pepper

1/4 teaspoon salt

2 ounces sharp cheddar cheese, shredded (about 1/2 cup)

1 ounce Parmesan cheese, grated (about 1/4 cup)



1. Preheat broiler.



2. Prepare broccoli in microwave according to package directions.



3. Heat a large ovenproof skillet over medium-high heat. Add oil to pan; swirl to coat. Add onion and mushrooms; cook 12 minutes or until mushrooms brown and liquid evaporates, stirring occasionally. Sprinkle mushroom mixture with flour; cook 1 minute, stirring constantly. Stir in milk. Bring to a boil; cook 3 minutes or until thick and bubbly. Stir in broccoli and chicken; cook 1 minute. Remove pan from heat. Stir in yogurt, mayonnaise, pepper, and salt. Top evenly with cheeses; broil 2 minutes.