In a medium saucepan, melt the butter and add the flour and salt.
Whisk it together and cook it for about one minute. It may be clumpy
While whisking constantly, slowly pour the milk in, only pouring about ½ cup at a time. Whisk and cook until it thickens, then pour more milk in, repeating this step until all of the milk is incorporated.
Cook and stir constantly for about 8-10 minutes until the milk mixture has slightly thickened.
Add a large handful of cheese and stir it in until melting.
Repeat step 6 until all of the cheese has melted and cook it for 5-10 minutes until it reaches the thickness you want it to be.
Serve warm with tortilla chips and enjoy!
Notes
*Traditional restaurant style white queso is thinner than other queso dip or nacho cheese. If you prefer your queso dip to be on the thicker side, use only 1 ½ cups of milk.