01 -
Melt the butter in a big skillet over medium heat. Toss in your thinly sliced onions and add the sugar. Let them cook, giving them a stir now and then, until they turn deep golden and develop a sweet flavor, around 20-25 minutes. When they stick to the pan, just splash a bit of beef broth to loosen them up.
02 -
Grab a bowl and mix your ground beef with salt, pepper, and Worcestershire sauce. Form this mixture into 4 equal-sized patties.
03 -
Put your patties on a hot grill or in a skillet and cook them how you like them.
04 -
Want tasty buns? Mix chopped garlic with some soft butter and spread it on your buns. Toast them until they're golden.
05 -
Take the bottom half of each bun and put a cooked patty on it. Add a big scoop of those sweet onions and top with your cheese slice.
06 -
Put your open-faced burgers under the broiler for a minute until the cheese gets all melty and bubbly.
07 -
Scatter some thyme on the melted cheese, pop the top bun on, and eat them while they're hot.