1/3 cup toasted pepitas (shelled pumpkin seeds)
2/3 cup thick Mexican crema or crème fraîche
1/2 tablespoon agave nectar or honey
1 clove garlic, chopped
3 ears shucked sweet corn
1/4 teaspoon chipotle chili powder
2 tablespoons mayonnaise
1 tablespoon fresh lime juice
1/3 cup crumbled cotija cheese
2 pounds ground chuck
1/3 cup finely chopped red onion
1 teaspoon chipotle chile powder
1/2 teaspoon oregano
2 teaspoons kosher salt
1/2 teaspoon freshly ground black pepper
Vegetable oil, for brushing on the grill rack
8 ounces queso quesadilla, queso Chihuahua, or Monterey Jack cheese, grated
6 hamburger buns, split
2 cups blue corn tortilla chips
Prepare a medium-hot fire in a charcoal grill with a cover, or preheat a gas grill to medium-high.
To make the crema, combine all of the ingredients in a food processor and process until smooth.
To make the esquites, grill the corn, turning occasionally, until lightly charred on all sides, 6 to 8 minutes. Remove, and when cool enough to handle, cut the kernels off the cob. Combine the corn with the rest of the ingredients and mix well. Cover and refrigerate.
To make the patties, combine all of the ingredients in a large bowl and mix gently but thoroughly. Form the mixture into 6 patties.
Brush the grill with vegetable oil. Place the patties on the grill, cover and cook, 4 to 5 minutes on each side. During the last 2 minutes of cooking, top the patties with equal amounts of cheese and place the buns, cut side down, around the outer edges of the grill to lightly toast.
To assemble the burgers, spread a generous amount of the crema on the toasted sides of buns. On each bun bottom, place a cheese-topped patty, a generous amount of the esquites, and a layer of the chips. Add the bun tops and serve.