This easy broccoli au gratin casserole can be made with fresh or frozen broccoli folded into a simple cultured butter and cheese roux. Crispy fried onions add crunch to this creamy, sublime side dish that can be prepped ahead of any meal.
Course Side Dish
Cuisine American
Keyword broccoli gratin
Prep Time 20 minutesminutes
Cook Time 25 minutesminutes
Total Time 45 minutesminutes
Servings 10
Calories 232kcal
Ingredients
3poundsbroccoli , cut into florets *see notes if using frozen broccoli*
Preheat the oven to 375°F. Steam the broccoli until tender in the microwave with ¼ cup water for 5-7 minutes, or in a steamer basket on the stove for 12-15 minutes. Drain.
While the broccoli is cooking, melt 1 tablespoon of the cultured butter in a non-stick skillet over medium heat. Add the onion and garlic and cook until the onion softens and the garlic is fragrant, for 3-4 minutes. Add the remaining cultured butter to the pan, melt, and sprinkle with the flour. Cook stirring for 2 minutes. Add the bay leaves and slowly add the milk while stirring, whisking away the floury lumps. Cook until the sauce thickens, stirring occasionally, about 7-8 minutes. Stir in the Parmesan cheese, kosher salt to taste, and nutmeg, and keep warm.
Fold in the cooked hot broccoli to the bubbly cheese sauce, tossing to coat. Transfer to a buttered 2-quart baking dish and top with the crispy fried onions. Bake for 15 minutes or until the sauce is bubbly and the crispy onions are golden. Serve warm.
Notes
If using frozen broccoli, purchase frozen broccoli florets rather than chopped broccoli.Thaw and drain the same amount of broccoli as called for fresh. Cook the broccoli until tender before folding it while still hot into the roux.