Broccoli Rice Casserole

Ingredients (13)

• 4 cups fresh broccoli florets
• 3 Tbsp unsalted butter
• 3/4 cup chopped onion
• 2 cups chopped portobello mushrooms
• 3 Tbsp all-purpose flour
• 1/2 cup chicken broth
• 1 12 oz can evaporated milk
• 1 tsp mustard powder
• 1 tsp salt
• 1/2 tsp black pepper
• 1/2 tsp garlic powder
• 3 cups shredded cheddar cheese
• 2 cups cooked rice