This unbelievably gooey queso is impossible to stop eating. It’s surprisingly simple to make, yet will add some serious flair to your campout or backyard barbecue. We like to make this dip in a cast-iron skillet because it conducts heat well (keeping your queso warm longer) and you can wrap a towel around the handle and bring it right to the table. We’ve included instructions for how to make this dip over a campfire or on your grill, but you can also whip it up on the stovetop to go with your weeknight taco spread. We also suggest charring your tortillas first and then wrapping them in foil to keep warm on the edge of your campfire or grill. This way you’ll be ready to serve your queso when it’s hot and ready for a dip.
Preheat a grill or prepare a campfire for moderately-high heat. Oil the grate. Skewer the cherry tomatoes and grill, turning occasionally, until lightly charred and beginning to blister, 5 to 7 minutes. Transfer to a plate and season with salt and black pepper. Cover the tomatoes with foil while you prepare the queso.
In a medium bowl, toss the shredded cheeses with the flour.
In a medium cast-iron skillet (about 8-inches), melt the butter over moderate heat (you can do this by lowering the heat on your grill or moving your skillet to the edge of the fire). Add the garlic and cook, stirring, until fragrant, about 1 minute. Add the beer and bring to a simmer. While stirring constantly, add the cheese a small handful at a time, letting it melt and become smooth between additions. Remove the skillet from the heat.
Remove the tomatoes from the skewers and pile on top of the queso. Garnish with small cilantro sprigs and thinly sliced serrano pepper, if using. Serve the queso right away with warm flour tortillas and lime wedges. If the queso begins to cool, set the skillet back on the grill or campfire grate to warm up.
NOTE If using wood skewers, soak them in water for at least 1 hour before using. If you do not have skewers, you can also wrap the cherry tomatoes up in a foil pouch and set directly on the grate or nestle into the edge of the coals around your campfire.