1-First Step: Prepare the mise en place. Divide 1 1/3 pounds 80/20 ground beef into 4 equal portions of about 1/3 pound each. Gently form each into thin oval patties, roughly 1/4-inch thick and matching rye bread size. Season both sides with 1/4 teaspoon salt and pinch of black pepper per patty. Slice 2 large onions thinly. This setup ensures even cooking for the classic diner patty melts recipe. For dietary tweaks, use turkey or veggie patties here.

2-Second Step: Caramelize the onions. Melt 1 tablespoon butter in a large skillet over medium-low heat. Add sliced onions and cook, stirring occasionally, for 15-20 minutes until soft and golden brown. Add a splash of water if they stick. These caramelized onions patty melt component builds deep flavor. Low-calorie option: Use cooking spray. Vegan cooks can proceed as is.

3-Third Step: Cook the beef patties. Increase skillet heat to medium. Remove onions to a plate. Add patties to the skillet, cooking 3-4 minutes per side until browned and medium doneness (160°F internal). Work in batches if needed. Juiciness comes from thin shape and 80/20 fat. For gluten-free or low-cal, no changes needed here. Transfer to a plate.

4-Fourth Step: Assemble the sandwiches. Butter one side of each rye bread slice with remaining softened butter. Place 4 slices butter-side down in the skillet. Layer each with 1 slice Swiss cheese, 1 patty, one-quarter of caramelized onions, another Swiss cheese slice, and top bread slice butter-side up. Press gently with spatula.

5-Fifth Step: Grill the patty melts. Cook over medium heat for 2-3 minutes per side, pressing down to compress and melt cheese. Bread should turn golden and crisp. Flip carefully. Use a lid for extra melt if desired. This step defines the traditional patty melt on rye bread.

6-Final Step: Serve hot. Slice diagonally and pair with fries, pickle spears, or salad. Rest 1 minute for juices to settle. Adapt for busy schedules by pre-caramelizing onions. Check out this classic patty melt recipe for more inspiration.