Melt 1 Tablespoon of butter in a small saucepan over medium heat
Sprinkle flour over the butter, whisk until combined
Lower heat a little and add the cheese and milk. Whisk until the cheese is melted - It should be a thick paste. At this point, you could add salt, pepper, or even hot sauce to taste
Remove from the pan from heat and slowly stir until smooth. If it seems too thick, simply add a couple of tablespoons of milk
Store leftovers in an airtight container in the refrigerator. Reheat on the stove or in a mini crockpot. If I am going to have the cheese out for a party or for a while, I will put it in my mini crockpot to keep it smooth and warm. You can also easily make this dip ahead of time and simply warm up when you're ready to serve.