Start by placing the ribeye steak in the freezer for about 30 minutes, which makes it easier to slice. Once firm, remove it and, using a sharp knife, cut the steak into thin strips, approximately 2mm thick.

In a mixing bowl, combine soy sauce, gochujang, minced ginger, light brown sugar, rice wine, minced garlic, black pepper, grated apple, and sesame oil. Add the sliced steak to the marinade, making sure it’s fully coated. Let it marinate for at least 30 minutes.

Heat a large skillet over high heat, adding vegetable oil once it’s hot. Carefully place the marinated steak strips into the pan, spreading them out for even cooking. Sear for about 4-5 minutes until the steak is nicely caramelized; stir occasionally and discard any excess liquid.

In the same skillet, add sliced red and yellow bell peppers. Stir-fry them over medium heat for about 2-3 minutes until they soften slightly and become vibrant in color.

Take your thick slices of bread and brush one side of each slice with melted butter. Lay them, butter-side down, on a work surface. Layer the sautéed peppers, followed by the cooked steak, and sprinkle sesame seeds, grated cheddar cheese, red onion slices, jalapeños, and sliced spring onions on top.

Carefully place the assembled sandwiches in the same skillet or a sandwich press over low to medium heat. Grill them for about 2-3 minutes per side, adjusting the heat as necessary, until the bread is golden brown and the cheese has melted beautifully.

While the sandwiches are cooking, prepare the sauce by mixing mayonnaise with the minced garlic in a small bowl.