There are many acceptable ways to formulate good queso, but to make this specific queso the ingredients must be correct, and most copycat recipes seem to get it wrong. A few recipes get one of the peppers and two of the cheeses right, but pretty much every recipe out there is a bit of a mess that I will now save you from.
Quesos can be made with a variety of cheeses that include queso fresco, asadero, and Muenster, but this particular queso includes a cheese you probably didn’t expect: Swiss. That cheese is slow to melt, so we’ll shred it first, along with the Jack. And you won't need to gum up the queso with flour or cornstarch by making a roux because the white American cheese in the mix contains sodium citrate or sodium phosphate—additives that help the cheese melt smoothly and stay that way.
Authors of recipes that call for tomatoes in this dish haven’t looked closely. Those are red bell peppers and they are roasted, peeled, and seeded along with the poblano and jalapenos before they are diced and added to the cheese sauce. The sauce cooks on low heat, never bubbling, so that it stays smooth and creamy.
When done, the queso might seem thin in the pan, but it will thicken as it cools to a perfect consistency for dipping tortilla chips, or as a topping for tacos and burrito bowls.
Find my recipes for Qdoba Adobo Chicken and Habanero Salsa here.