Diner-Style Patty Melts

1. Preheat Oven

Start by adjusting your oven rack to the middle position and preheating the oven to 200 degrees. This is to keep the sandwiches warm as you finish cooking them.

2. Prepare Seasoning

In a small bowl, mix together 1.5 teaspoons of kosher salt and 1 teaspoon of pepper to use for seasoning the patties.

3. Make Ketchup Mixture

In another small bowl, combine 0.5 cups of water, 2 tablespoons of ketchup, 2 tablespoons of cider vinegar, 2 teaspoons of packed brown sugar, and 2 teaspoons of Worcestershire sauce. This mixture will be used to caramelize the onions later.

4. Prepare Bread and Cheese

Lay four slices of lightly toasted rye bread on a clean counter. Shingle one slice of Swiss cheese and one slice of American cheese on each piece of toast. This will help the cheese melt evenly over the patties.

5. Form Patties

Divide the ground beef into four portions and press each into a thin oval patty that is about 0.25 inches larger than the rye toast. This ensures the patty fits perfectly in the sandwich.

6. Cook Patties

Heat a 12-inch cast-iron skillet over medium-high heat for about 5 minutes. While the skillet is heating up, season the beef patties with the salt and pepper mixture. Add 1 tablespoon of butter to the skillet and cook two of the patties for 60 to 90 seconds per side, until they are nicely browned. Transfer the cooked patties onto the cheese-topped slices of rye toast. Repeat this process for the remaining patties, using another tablespoon of butter.

7. Caramelize Onions

In the same skillet, add the sliced onions along with 1 cup of water, the remaining 0.5 teaspoons of salt, and 0.5 teaspoons of pepper. Cook the onions for about 8-10 minutes, stirring occasionally until the water has evaporated and the onions have started to soften. Continue cooking the onions for another 5-7 minutes until they are softened and caramelized. Stir in the ketchup mixture and cook for an additional 5-7 minutes until the onions are uniformly browned. Divide the caramelized onions over the patties and top each with another slice of Swiss cheese, then cover with the remaining slices of rye toast.

8. Cook Sandwiches

Wipe out the skillet with paper towels and add 1 tablespoon of butter. Place two of the assembled sandwiches into the skillet and cook over medium heat for 3-5 minutes until the bottoms are golden brown. Flip the sandwiches, adding another tablespoon of butter to the skillet, and cook for about 3 more minutes until the second side is golden brown. Transfer the cooked sandwiches to a wire rack in the oven to keep warm. Repeat this process for the remaining sandwiches, using the last 2 tablespoons of butter.

9. Serve

Once all the sandwiches are cooked, slice them in half and serve immediately. Enjoy your delicious diner-style patty melts!