Fill a medium saucepan with 1 inch of water and place a steamer inside. Bring the water to a boil, place the broccoli in the steamer, reduce the heat to medium, cover and steam until tender and bright green, about 5 minutes.
Transfer the broccoli to a bowl and sprinkle lightly with salt and pepper. Top the broccoli with the Cheddar Cheese Sauce, or serve it on the side.
Melt the butter in a medium saucepan over medium heat until foamy. Spoon the flour over the butter and cook, while stirring, until the flour becomes pasty. Pour in the milk while whisking and season with salt and pepper. Bring to a boil, reduce the heat to a medium simmer and cook for 5 to 8 minutes. Slowly add the cheese by handfuls and stir with a wooden spoon until melted and smooth.