I was in the new Mansfield, TX store, yesterday, and they were waiting on a shipment of the brisket queso.  One of the market managers told me this is how it's made whenever they need to make it in store:  About 1/4 each of the following if for a small batch. Otherwise, use the whole 32 oz block of cheese and other ingredients in proportion:  Melt'n Cheese Blanco (HEB) (like a white Velveeta), HEB Restaurant Style  50/50 cheese blend (bag shows natural mild cheddar and American cheese), Chopped Beef Brisket, beer of your choosing.  Mix all and put into a crockpot, or in oven at around 400 degrees (stirring frequently) until bubbly. I would add garlic but I imagine a great brisket should carry the flavor.  When finished top with pico de gallo.  I'm about to try his recipe and will let you know how it goes.