This homemade nacho cheese sauce is a simple butter-and-flour roux finished with whole milk and freshly shredded cheddar — just $0.26 a serving, ready in 10 minutes, and the smooth, creamy party dip that beats every store-bought jar on the shelf.
In a small saucepan over medium heat, melt butter.
Add flour and whisk continuously for about 1 minute until the mixture is smooth, combined, and lightly thickened.
Slowly pour in whole milk, whisking constantly to prevent lumps.
Increase the heat slightly and continue whisking as the mixture comes to a gentle simmer. Cook until the sauce thickens enough to coat the back of a spoon, about 3–5 minutes.
Remove the saucepan from the heat.
Gradually add shredded cheddar cheese, a handful at a time, whisking after each addition until the cheese is completely melted and smooth.
Stir in salt.
If the sauce is thicker than desired, whisk in a little additional milk, 1 tablespoon at a time, until it reaches your preferred consistency.