Broccoli Gratin

5 from 22 votes

A delicious broccoli casserole with a creamy sauce and a crunchy topping.

Course Vegetable

Cuisine American

Prep Time 15

Cook Time 20

Steaming Broccoli 5

Total Time 40

Servings people

Calories 300kcal

Steam the broccoli for 2-3 minutes, just until the colors brighten and the broccoli begins to soften, just slightly. The broccoli will continue cooking in the casserole. You could also blanch the broccoli, just be certain to pat dry the broccoli before adding to the sauce.
1 pound broccoli florets
In a saucepan, melt the butter over medium heat. Stir in the flour and heat for about 1 minute, stirring often.
3 tablespoons butter, 3 tablespoons flour
Add salt and dry mustard.
½ teaspoon salt, ½ teaspoon dry mustard
Slowly whisk in the milk. Heat until the sauce begins to thicken. The sauce should coat the back of a spoon and stay separated when you draw a line through the center of the spoon.
2 ¼ cups milk
Turn heat off and slowly whisk in the cheese.
6 ounces shredded cheese
Add the sauce to the prepared broccoli.
Place broccoli in a lightly greased casserole dish.
Melt the remaining butter and toss with the panko breadcrumbs.
2 tablespoons butter, ½ cup panko breadcrumbs
Sprinkle over the broccoli.
Add Parmesan cheese over the top. Add an additional pinch of coarse salt across the top.
¼ cup parmesan
Bake in a preheated 400°F oven for 20 minutes or until the casserole is bubbly and browned on top.
Remove from oven and allow the casserole to cool for 10 minutes before serving.

Make certain you turn off the heat before stirring in the cheese. This helps prevent the sauce from breaking.

Bake the casserole on a sheet pan. This will catch any drips if the casserole boils over.

If you want an even browner topping, pop under the broiler after the casserole is fully cooked.
You can make and assemble the casserole up to one day ahead of time. Cover and refrigerate. Before baking, allow the casserole to sit on the counter and come to room temperature for at least 30 minutes. You may need to increase baking time by 5-10 minutes.