Queso Fundido Burger - Rick Bayless

Ingredients

• 2 medium fresh poblano chiles
• 8 ounces fresh Mexican chorizo sausage, removed from its casing if there is one
• 1 tablespoon vegetable oil
• 1 medium onion, sliced 1/4-inch thick
• 2 garlic cloves, finely chopped
• 1 1/2 pounds ground chuck (chuck offers a beefy flavor and richness I like for special occasions when these burgers are appropriate; you can choose a leaner cut if that makes sense for you)
• 1 to 2 canned chipotle chiles en adobo, finely minced, seeded if you wish
• 8 thick slices Monterey Jack Cheese
• 4 hamburger buns, lightly toasted