Chili-Pie Burgers

Preheat oven to 350°F. Heat oil in a skillet over medium; add onion and garlic. Season and cook until translucent, 3 minutes. Add chili powder; cook 30 seconds. Stir in ketchup; cook 1 minute. Shape beef into 4 patties, each a scant 1/2 inch thick; season.

Place 1 slice cheese on bottom half of each bun; place separated tops and bottoms on a baking sheet and toast in oven while burgers cook. Meanwhile, heat a large, heavy skillet (preferably cast iron) over medium-high.

Add burgers and cook, pressing with a spatula, until browned, about 3 minutes. Flip; reduce heat to medium. Top each burger with a quarter of onion mixture and a slice of cheese. Cover and cook until cheese melts, about 1 minute. Serve on buns with lettuce, jalapeños, and chips.