Ingredients:
-
- Approximately forty-five minutes
- Output: four sandwiches
- One tablespoon of olive oil
- 2 cups of finely sliced onion from 1 big onion
- Six tablespoons of unsalted butter, divided
- Garlic powder and kosher salt
- 2 tablespoons of ketchup
- 1 and a half pounds of lean ground beef
