Double Cheddar-Chili Burgers

Ingredients

6 ¼-inch thick slices sweet onion, such as Vidalia
1 (10.6-oz.) bottle chili garlic sauce, divided
1 pound ground chuck
1 pound ground sirloin
1 very ripe California avocado, mashed
6 (1-oz.) chunks extra sharp cheddar cheese
3 tablespoons kosher salt
½ tablespoon freshly ground pepper
Vegetable oil, for brushing the grill rack
6 tablespoons unsalted butter, softened
6 soft kaiser rolls, split
1 cup shredded sharp cheddar cheese
6 romaine lettuce leaves

Instructions

Preheat a gas grill to medium-high. Place onion slices in a 9×13” glass pan. Brush 9 tablespoons of the chili garlic sauce evenly over the onions; cover and set aside. To make the patties, combine the chuck, sirloin, avocado and remaining chili garlic sauce in a large bowl. Handling the meat as little as possible to avoid compacting it, mix well. Divide the mixture into 12 equal portions that are slightly thicker in the center and fit the rolls. Top 6 of the patties with a chunk of cheddar cheese. Place remaining patties on top, pinching the edges to seal. Sprinkle salt and pepper evenly on both sides of patties. Brush the grill rack with vegetable oil. Place the patties on the rack and grill, covered, 1 ½ minutes on each side to sear. Reduce heat to medium. Cover and grill 5-7 minutes on each side for medium. During the last few minutes of cooking, spread butter on cut sides of rolls; place on outer edges of grill rack cut side down, to toast slightly. Sprinkle grated cheese evenly on top of burgers. To assemble the burgers, on each roll bottom, place a lettuce leaf, a patty and a slice of onion with sauce. Add the roll tops and serve. Makes 6 burgers