3 tablespoons unsalted butter
1/3 cup all-purpose flour
2 3/4 cups whole milk - warm but not hot
4 oz grated Cheddar cheese
6 oz cooked macaroni noodles
In a heavy-bottomed saucepan, melt the butter over medium-low heat, then stir in the flour to form a roux. Cook the roux for 2 to 3 minutes, stirring constantly.
Slowly add 2 1/2 cups of the milk while whisking or stirring constantly so that the liquid is incorporated into the roux without forming lumps. Bring to a boil, reduce to simmer for 3-5 minutes.
Remove from heat, Add the cheese and stir until the cheese has melted.
Add freshly cooked pasta, season with salt and serve