In a large skillet over medium-high heat, crumble and brown 1 pound of lean ground beef until fully cooked, about 8-10 minutes. Drain excess grease, then transfer to a stock pot. Add diced tomatoes, brown sugar, and other chili ingredients. Stir and bring to a boil, then simmer for about 1 hour.

While the chili simmers, form the leftover ground beef into four patties, season with salt and pepper. Preheat grill to medium heat, about 375°F. Grill patties for about 7 minutes per side, until desired doneness. In the last minute, place a slice of cheese on each patty to melt.

Assemble the burgers by placing each cheese-covered patty on the bottom half of a bun. Spoon about 1/4 cup of simmered chili over each patty, drizzle a tablespoon of queso cheese dip, and add crispy onion strings.

Complete assembly with the top half of the bun. Serve immediately with sides like fries or salad.