Sauté the onion and garlic in a nonstick pan in a splash of oil until softened; cool.

Mix beef with onion, garlic, crumbs, egg, minced chipotle peppers and sauce, chili powder, salt and pepper, tossing together lightly but until thoroughly mixed. Shape into 6 to 7 patties. Cover and chill for 30 minutes ideally.

Cook in a lightly oiled hot cast iron pan or on an oiled hot grill. Cook, over medium heat, turning several times until digital instant-read thermometer inserted sideways into the centre of each patty reads 160°F (71°C). Serve each on toasted buttered buns.