If you cant find american cheese. You can use Velevetta but then you have to melt your cheese stove top or in the microwave and slowly as it will scorch easily..
If you have ever had Pancho Dip .This is as close as you get. If you buy it in the store ,a small container is 6 Dollars when this makes so much More.
Hope you enjoy and can understand my vague instructions on amounts of seasoning and milk as it depends on the person making it.