Ingredients

• 1 1/2 pounds ground beef, 80/20
• 1/4 teaspoon dried oregano, preferably Mexican
• 1/4 teaspoon kosher salt
• 1/8 teaspoon garlic powder
• Freshly ground black pepper
• 1/2 cup sour cream
• 3 chipotle chiles in adobo sauce, finely chopped, plus 3 tablespoons adobo sauce
• 1/3 cup finely chopped white onion
• 1 cup loosely packed fresh cilantro leaves, finely chopped
• 1/4 teaspoon kosher salt
• Freshly ground black pepper
• 4 whole-wheat buns, split
• 2 tablespoons unsalted butter, softened
• 4 slices Cheddar
• 1 avocado, thinly sliced
• Tomato slices, for topping
• Green-leaf lettuce leaves, for topping
• Red onion slices, for topping

Instructions

1. To make the patties: Combine the beef, oregano, salt, garlic powder, and pepper to taste in a medium bowl and mix well. Shape into patties a little more than 1/2-inch thick, place on a plate, and refrigerate for at least 1 hour.
2. To make the sauce: Stir together the sour cream, chipotles, adobo sauce, onions, cilantro, salt, and pepper to taste in a small bowl. Set aside.
3. To make the burgers: Oil a grill rack and preheat the grill on high for 5 minutes. Spread the bun faces lightly with the butter. Grill the burgers over direct heat on medium-high (on a charcoal grill, set the burgers just outside the center of the grill rack), with the grill covered, for 4 minutes. Flip the burgers, top each with a slice of Cheddar, and grill, covered, 4 minutes more. Remove the burgers to a plate.
4. Grill the buns, buttered-side down, over indirect heat, until golden, about 2 minutes. Set a burger on each bun bottom and top with avocado, tomato, lettuce, red onion and a dab of chipotle sauce. Top with the remaining bun halves and serve.