Chipotle Pork Cheeseburger

INGREDIENTS
1 pound ground pork (not lean)
2 teaspoons minced chipotle in adobo plus 1 teaspoon adobo sauce 2 garlic cloves, forced through a garlic press
4 slices Muenster cheese
4 hamburger buns, toasted
1/4 cup mayonnaise
1 large tomatillo (1/4 pound), husked and rinsed, then sliced
1/2 small avocado, sliced
1/2 cup cilantro sprigs

INSTRUCTIONS
Prepare a gas grill for direct-heat cooking over medium heat.
Gently mix pork, chipotle, garlic, and a scant teaspoon salt until just combined.
Form into 4 (1/2-inch-thick) patties.
Oil grill rack, then grill patties, covered, 4 minutes.
Flip patties and top with a slice of cheese.
Grill, covered, until just cooked through, 1 to 2 minutes more.
Spread buns with mayonnaise and assemble burgers with tomatillo, avocado, and cilantro.

Cooks' note:
Burgers can be grilled in an oiled hot 2-burner grill pan over medium heat, about 10 minutes total.