For the Sandwich
- 1 lb. ground beef
- ½ tsp. kosher salt
- ¼ tsp. pepper
- 6 tbsp. butter, softened, divided
- 1 lg. onion, sliced
- 6 slices rye bread
- 6 slices sharp cheddar cheese
- Chips and a pickle for serving
For the Sauce
- 1 c. mayo
- 1 tbsp. finely chopped onion
- ¼ c. ketchup or chili sauce
- 4 tsp. prepared horseradish
- 1 tsp. hot sauce
- 1 tsp. Worcestershire sauce
- ¼ tsp. smoked paprika
- Salt and pepper to taste
- Make the dressing by mixing all of its ingredients together in a bowl with a whisk. Set aside.
- Divide the beef into 3 equal portions. Try to form the meat into patties that are close to the same shape as the bread you are using.
- Make an indentation in the center of each patty to prevent from ballooning up while cooking.
- Season with the salt and pepper on both sides. Set aside.
- Melt 2 tbsp. of the butter in a saute pan over med-high heat and add the onions, salt, and pepper.
- Cook the onions 8-10 minutes or until softened and are beginning to caramelize.
- Remove from the pan and set aside.
- Add a little more oil to the pan and reheat over med-high heat.
- Place the hamburger patties into the pan and cook about 4-5 minutes per side.
- Remove the mostly cooked patties from the pan and set aside.
- Preheat an electric griddle to 275 or preheat a non-stick pan over medium heat.
- Spread the remaining butter on one side of each slice of bread.
- Place 3 slices of bread, buttered side down, on the griddle.
- Spread some of the sauce on the 3 slices of bread, opposite the butter.
- Place a slice of cheese on the bread, followed by one of the patties, 1/3 of the onions, and then one more slice of cheese.
- Repeat the process to build the other sandwiches.
- Top each sandwich with a slice of the bread, the buttered side up, and sauce spread on the other side.
- Cook for 3-4 minutes per side or until golden brown and the cheese is melty.
- Slice in half and enjoy!