Delicious Patty Melt Grilled Cheese

1. Caramelize the Onions:
   In a large heavy-based frying pan, heat 1 tablespoon of butter along with half the olive oil over medium heat. Add the sliced onion and a pinch of salt. Cook for 20-25 minutes, stirring occasionally, until the onions become golden and sticky.

2. Prepare the Burger Patties:
   In a bowl, combine the beef mince with garlic granules, Worcestershire sauce, and seasoning. Mix with your hands until the mince has a fine texture. Divide the mixture into two balls and flatten them into patties, shaping them to match the size of your bread (making them slightly oblong if using a bloomer loaf is recommended).

3. Cook the Patties:
   Once the onions are done, transfer them to a plate. In the same pan, heat the remaining oil over high heat. Fry the burger patties for 3-4 minutes on each side, pressing down with a spatula, until they are golden brown and cooked through. Once cooked, place them on a plate and scrape any flavorful bits from the pan over the patties.

4. Toast the Bread:
   Lower the heat to medium-low and add ½ tablespoon of butter to the pan, swirling it around to coat the base. Fry all four slices of bread on one side, pressing them down with a grill press or spatula to achieve an even golden crisp. Do this in two batches, adding another ½ tablespoon of butter for the last two slices. In a bowl, mix the grated cheddar and Swiss cheese together.

5. Assemble the Toasties:
   Lay two of the toasted bread slices on a board, toasted-side up. Spread Dijon mustard over them, then sprinkle half of the cheese mixture. Evenly spoon the caramelized onions on top, followed by the burger patties. Add the remaining cheese on top. Place the other two slices of bread on top, toasted-side down, so the untoasted sides are on the outside. Press down firmly to seal the sandwiches.

6. Fry the Sandwiches:
   Heat the remaining butter in the pan, then fry the sandwiches for 2-3 minutes, pressing down to ensure they become golden and crispy. Carefully flip the sandwiches, adding any remaining butter to the pan around them. Cook until the cheese is melted and gooey, and the bread is golden brown on both sides.

Tips:

• What is a Patty Melt?
  A patty melt is a classic American diner dish that combines elements of a burger and grilled cheese sandwich. Traditionally made with rye bread and American cheese, this version uses Dijon mustard and cheddar, making it delicious with homemade sourdough.

• Spicy Kimchi Patty Melt:
  Omit step one. Instead, add a spoonful of gochujang and a pinch of sesame seeds to the cheese mixture in step four. Layer the toastie with kimchi and sliced spring onions instead of caramelized onions in step five for an umami twist.

• Reuben-Style Patty Melt:
  Replace the burger patties with thick slices of salt beef or layers of pastrami. Add sauerkraut along with the cooked onions in step five, and include sliced pickles for a deli-inspired flavor.