Cheese Sauce For Philly Cheese Steaks - cooking recipe

Ingredients

1 1/2 tablespoons butter
1 1/2 tablespoons flour
1/2 cup milk, divided
1 - 1 1/4 cup cheddar cheese, grated (whatever sharpness you prefer)
6 ounces Velveeta cheese, cut into small chunks (the small chunks allow it to melt more quickly)

Preparation

In a small saucepan, melt the butter on low heat.
Once melted, gradually add the flour, stirring constantly to avoid lumps, about 2 minutes.You should end up with a thick but still stirrable roux (A roux is basically just equal part butter and flour stirred over some heat and then you add your liquid ingredients to it. It's a thickener and can be used to start all sorts of cream sauces).
Add 1/4 cup milk slowly to the roux and cook over low heat. Stir until it thickens, about 2 minutes.
Add the cheddar cheese, the remaining 1/4 cup milk and Velvetta and cook, stirring frequently, until you have a smooth cheese sauce, about 5 minutes.