For the burgers:
- 1 1/2 pounds 80% lean ground beef
- 1/4 pound good-quality smoky bacon (uncooked), finely chopped
- 2 round tablespoons pureed chipotle in Adobo sauce
- 2 tablespoons Worcestershire sauce
- 2 cloves garlic, finely chopped or grated
- 3-4 tablespoons grated onion
- Salt and pepper
- Vegetable or olive oil for drizzling
For the 3-cheese queso:
- 2 tablespoons butter
- 1 round tablespoon flour
- 1 cup milk
- About 1 1/2 cups grated Manchego cheese (1/3 pound)
- About 1 cup shredded Monterey Jack cheese (1/4 pound)
- About 1/4-1/3 cup grated Parmigiano Reggiano cheese (a couple of small handfuls)
- 6 burger rolls, split
For the toppings:
- Crispy tortilla chips – blue, yellow or multigrain
- Minced red onions
- Chopped cilantro
- Chopped seeded tomato
- Pickled jalapeño slices
Combine the beef with the bacon, chipotle puree, Worcestershire sauce, garlic, onion, salt and pepper. Form six patties that are thinner at the center and thicker at the edges for even cooking. Drizzle with a little oil.
Heat a cast iron skillet or double-burner griddle pan over medium-high heat.
Melt the butter in a small pan over medium heat. Whisk in the flour, cook for 1 minute, then add the milk. Cook to thicken, then melt in the cheeses.
Meanwhile, grill the burgers for 5 minutes on each side for medium, a minute less per side for rare, a minute more per side for medium-well doneness.
Place the burgers on the bun bottoms and top with the cheese sauce, chips and toppings. Set the bun tops in place and serve.