- 1 pound broccoli, cut into 1-inch florets with about 2 inches of stem
- 3 tablespoons unsalted butter
- 3 tablespoons all-purpose flour
- 1 1/4 cups milk
- 1/4 cup heavy cream
- 1/4 teaspoon dry mustard mixed with 1/2 tablespoon water
- 6 ounces sharp or mild white cheddar cheese, shredded (1 1/2 cups)
- Kosher salt
In a large, deep saucepan, bring 1 inch of water to a boil. Fill a steamer basket with the broccoli, add it to the saucepan, cover and steam over high heat until the broccoli is crisp-tender, about 5 minutes. Transfer the broccoli to a platter.
Meanwhile, in a saucepan, melt the butter. Add the flour and whisk over moderately high heat for 2 minutes. Add the milk and cream and cook, whisking, until thickened, about 2 minutes. Add the mustard and cheese and cook over moderately low heat until the cheese is melted. Season the sauce with salt, transfer to a bowl and serve with the broccoli.