In a medium bowl, add the crushed Saltine crackers, 4 tablespoons of melted butter, 1/4 cup of shredded cheddar cheese, 1/4 teaspoon salt, and 1/4 teaspoon pepper. Stir to combine and then set aside.
In a large pot over medium heat, add the remaining 2 tablespoons of butter, garlic, and flour. Stir constantly until golden and fragrant, about 1-2 minutes.
Slowly whisk in the cream and broth.
Stir in broccoli, cauliflower, dry mustard, 1/2 teaspoon salt, and 1/2 teaspoon pepper. Bring to a boil and then reduce heat to medium-low and simmer covered, stirring occasionally, until broccoli and cauliflower are nearly tender, about 5-8 minutes.
Remove pot from heat and stir in remaining cheese until incorporated. Pour mixture into a 9x13-inch dish.
Top with cracker crumbs.
Bake for 10-15 minutes, or until crumbs are golden brown and crisp. Cool for 10 minutes before serving.
To make this broccoli casserole ahead of time, follow all the directions to prepare your dish, but DO NOT add the cracker crumbs (you can store those in a plastic bag separately.) Cover the casserole with foil and place in the refrigerator overnight, or until you are ready to bake it. Bring the casserole to room temperature before topping with cracker crumbs and then bake it in the preheated oven.
You can use either yellow or white extra-sharp cheddar cheese in this recipe, I used white.
Pre-shredded cheese has starches and other added agents to it to prevent clumping. These additives aren't the best when you're making a cheese sauce! Because of this, I suggest using a block of cheese and grating it yourself.
Easy Broccoli Cheese Casserole
Amount Per Serving
Calories 479Calories from Fat 387
% Daily Value*
Saturated Fat 27g169%
Vitamin A 1457IU29%
Vitamin C 1mg1%
* Percent Daily Values are based on a 2000 calorie diet.