Basic cheese sauce

Some of my fondest childhood memories are eating my mom's steamed cauliflower slathered with cheese sauce after returning from trips¹. What follows is the Radagast and SO household standard cheese sauce recipe; while this isn't the fanciest cheese sauce, it's easy to make, reminds me of my mom's, and tastes, well, cheesy. Since we had cauliflower with cheese sauce last week, this is this week's end-of-the-week recipe blogging post.

1/4 cup (4 tablespoons) unsalted butter
1/4 cup (4 tablespoons) flour
2 cups milk
2 cups grated cheddar cheese (we use medium cheddar)
1/2 teaspoon kosher salt
1/4 teaspoon ground black pepper

0. Heat the milk in the microwave (or in a small saucepan over medium heat), but do not bring it to a boil.
1. Melt the butter in a non-stick saucepan over medium-high heat.
2. Add the flour, and, stirring constantly, cook until the flour browns slightly (probably around 3 minutes).
3. Remove the pan from the heat and let cool, stirring frequently, until the flour mixture stops bubbling.
4. Add the warmed milk to the flour mixture, return to the heat, and whisk constantly until smooth.
5. Cook, whisking frequently, until the sauce is somewhat thickened (probably about 5 minutes).
6. Add the cheese (adding it in two batches helps keep it from forming a giant, slow-to-dissolve blob) and stir until all the cheese is melted.
7. Add the black pepper and salt; taste, and adjust the seasonings to your liking.

Notes:

If you like nutmeg (which Radagast doesn't), a pinch or two might compliment the sauce's flavor.

This sauce should be served warm, as it thickens when it cools. A skin may form on the surface of the sauce if it sits for a while at room temperature; just stir this skin back into the sauce and it will be fine. If the mixture begins to thicken too much before you're ready to eat it, simply re-heat it on the stove (or in the microwave) briefly, stirring frequently.

¹ I still love cheese sauce on cauliflower, though these days I typically use roasted cauliflower as the base, not steamed.