Cheese Broccoli (Broccoli Au Gratin)
Creamy, cheesy, and baked to perfection, broccoli au gratin turns simple broccoli into a rich, comforting side. Tender florets are coated in a smooth cheese sauce and topped with a golden, bubbly finish. It’s an easy way to make vegetables feel a little more indulgent—and a lot more delicious.
Ingredients
- Cooking spray or butter (for coating the baking dish)
- 5 tablespoons unsalted butter
- 1 1/2 pounds broccoli crowns (about 3 medium or broccoli florets, cut into 1-inch pieces (8 to 9 cups total))
- 1/2 medium yellow onion (diced (about 3/4 cup))
- 8 ounces sharp cheddar cheese (2 cups shredded, preferably white)
- 3 tablespoons all-purpose flour
- 1/2 teaspoon dry mustard (or 1 1/2 teaspoons Dijon mustard)
- 2 cups whole or 2% milk
- 3/4 teaspoon kosher salt
- 1/3 cup panko breadcrumbs
- 2 tablespoons grated Parmesan cheese
Instructions
- Arrange a rack in the middle of the oven and heat the oven to 425ºF. Coat an 8-inch square or other 2-quart baking dish with cooking spray or butter and place on a baking sheet.
- Melt butter in a Dutch oven or large pot over medium heat. Transfer 1 tablespoon of the melted butter into a small, heatproof bowl.
- Add yellow onion to the melted butter in the pot and cook over medium heat, stirring occasionally, until softened, about 5 minutes. Sprinkle with flour and mustard and stir constantly for 1 minute. While stirring constantly, slowly pour in the milk and stir until the flour is completely dissolved. Bring just to a full simmer over medium-high heat, stirring frequently.
- Add shredded cheddar cheese and salt, and stir until the cheese is melted and the sauce is bubbling. Remove the pot from the heat, add broccoli, and stir until well-coated in the sauce. Transfer to the baking dish and spread into an even layer.
- Add breadcrumbs and grated Parmesan cheese to the reserved bowl of melted butter and stir to combine. Sprinkle the gratin with the breadcrumb mixture.
- Keeping the gratin on the baking dish to catch any drips, bake until the broccoli is tender and the sauce is bubbling, about 30 minutes. If you’d like a browner top, broil until the breadcrumbs are golden-brown, 2 to 3 minutes more. Let cool for 10 minutes to let the sauce thicken before serving.
