New Mexican Green Chile "Cheeseburgers"

Relish:

• 4 garlic cloves
• 1 Cubanelle pepper
• 1 serrano chile
• 1 medium tomatillo, papery skin removed
• Cooking spray
• 2 tablespoons chopped fresh cilantro
• 1 tablespoon finely diced red onion
• 1 tablespoon fresh lime juice
• 1 tablespoon olive oil 
• 1/2 teaspoon sugar
• 1/4 teaspoon kosher salt

Burgers:

• 6 (1/2-inch-thick) slices small red onion
• 1 1/2 tablespoons olive oil, divided
• 4 ounces cremini mushrooms
• 2 garlic cloves
• 1 (15-ounce) can unsalted black beans, rinsed and drained
• 1/2 cup plus 1 tablespoon whole-wheat panko (Japanese breadcrumbs)
• 1 tablespoon chopped fresh oregano
• 1 teaspoon ground cumin
• 1/2 teaspoon kosher salt
• 1/4 teaspoon ancho chile powder
• 1 large egg
• 2 ounces aged white cheddar cheese, thinly sliced
• 6 romaine lettuce leaves
• 6 whole-wheat hamburger buns, toasted 

Preheat broiler to high.

To prepare relish, place first 4 ingredients on a foil-lined baking sheet. Coat vegetables with cooking spray. Broil 14 minutes, turning vegetables once. Wrap Cubanelle and serrano in foil; let stand 10 minutes. Peel and cut into 1-inch strips; discard peels and seeds. Combine tomatillo, Cubanelle, serrano, garlic, cilantro, and next 5 ingredients (through 1/4 teaspoon salt) in a mini food processor; pulse until combined.

To prepare burgers, brush onion slices with 1 1/2 teaspoons oil. Arrange onion in a single layer on a foil-lined baking sheet. Broil 6 minutes or until lightly charred, turning once.

Combine mushrooms, 2 garlic cloves, and black beans in a food processor; pulse until mixture is coarsely chopped. Add panko and next 5 ingredients (through egg); pulse until combined. Divide mixture into 6 equal portions; shape each portion into a 1/2-inch-thick patty.

Heat a large cast-iron skillet over medium heat. Add remaining 1 tablespoon olive oil to pan; swirl to coat. Add patties; cook 12 minutes, turning once. Add cheese to patties during last 2 minutes of cooking; cover pan to melt cheese. Place 1 lettuce leaf on bottom half of each bun. Top each lettuce leaf with 1 patty, 1 charred onion slice, and about 1 1/2 tablespoons relish. Top with top halves of buns.

Serves 6; 286 calories.

VERDICT:  This was a little fussy, but not hard, and turned out pretty well.  Maybe skip making the relish and use salsa verde?  If so, keep.