- STEP 1
Grease a 9x13-inch casserole pan. Preheat oven to 400 degrees F.
- STEP 2
In a large saucepan melt the butter over low heat; add garlic and saute until fragrant.
- STEP 3
Whisk in flour and cook 3-4 minutes, whisking constantly. Slowly whisk in milk, mustard and season with salt and pepper, bring to a simmer 4 minutes, whisking occasionally.
- STEP 4
Add 2 cups of cheddar cheese and parmesan; stir until mostly melted; remove from heat.
- STEP 5
Stir in rice and broccoli florets, pour into casserole pan, sprinkle remaining 1/2 cup cheese over top. Bake 30 minutes until bubbly and lightly golden on top. Allow to set 5 minutes before serving.