Place butter in a saucepan set over low-medium heat. Once melted, whisk in the flour until combined.
Add milk and whisk to evenly mix. Keep whisking as the mixture begins to thicken, about 10 or so minutes, or until it’s to a point where it can thickly coat the whisk (or a spoon).
Once the mixture has begun to thicken, add the cheese. Stir or whisk frequently as the cheese melts and the sauce becomes smooth and creamy.
This sauce is ideal for pastas, lasagne, as a dip and much more.
