Wisconsin Butter Burger

Method

1. Cook the onion in 1 Tbsp butter with the water and ¼ tsp salt, covered, about 5 minutes. Uncover and cook until translucent and just browning, about 3 minutes. Keep warm.
2. Shape the beef into four patties 4½ in wide and ½ in thick. Season both sides with ¾ tsp each salt and pepper.
3. Spread 2 Tbsp butter on each top bun.
4. Sear the patties in the oil in a smoking-hot skillet for 3 minutes without moving, flip, cook 1 minute, add cheese and cook 30 seconds more.
5. Put the patties on the bottom buns, add the onions and close with the buttered tops so the butter melts into the burger.