Prep Time: 15 minutes
Cook Time: 35 minutes
Total Time: 50 minutes
Servings: 10
Heat oven to 375°F. Spray 13x9-inch (3-quart) glass baking dish with cooking spray.
Make potatoes as directed on box for stove-top directions with 4 cups boiling water, 1-1/3 cup milk and 2 Tbsp butter. Stir in mustard.
Add half the potatoes to baking dish, spreading evenly. Sprinkle broccoli over top. Pour remaining potatoes on top of broccoli. Sprinkle crushed crackers on top.
Bake 12 to 15 minutes or until sauce is bubbling. Let stand 5 minutes before serving (sauce will thicken as it stands).