Ingredients
Scale
- 2 lbs ground beef 80/20
- 12–14 slices Swiss cheese
- 1.5 cups Gruyere cheese, shredded
- 2 large yellow onions, thinly sliced
- 6–8 slices thick cut bread
- 2.5 tbsp kosher salt
- 2.5 tbsp black pepper
- 2 tbsp garlic powder
- 2 tbsp brown sugar
- 2 tbsp mayonnaise
- 2 tbsp ketchup
- 2 tbsp yellow mustard
- 1 tbsp pickled relish
- 1.5 tsp hot sauce
Instructions
- Form 2.5-3 oz beef balls and refrigerate for 30 minutes. Mix all diner sauce ingredients and refrigerate until ready.
- Preheat grill to 350°F. Add cast iron skillet 2 minutes before cooking.
- Add beef balls to hot skillet. Cover with parchment paper and smash firmly with spatula. Cook 1-2 minutes, flip, and season cooked side.
- Add sliced onions to skillet. Cook 30-45 minutes until dark brown. Add seasonings and brown sugar halfway through.
- Layer sandwich: bread with sauce, onions, Gruyere, patty, Swiss, patty, Swiss, onions, Gruyere, bread with sauce.
- Cook assembled sandwiches on clean skillet 1-2 minutes per side until golden. Cool briefly and serve with fries and pickles.
Notes
- Chill beef balls before cooking to maintain shape and prevent overcooking during the smashing process
- Use parchment paper when smashing to prevent sticking and ensure even pressure distribution
- Don’t rush the onion caramelization – low and slow cooking develops the best flavor and color
- Layer cheese strategically to create maximum melting and flavor integration throughout the sandwich
- Toast assembled sandwiches on medium heat to ensure cheese melts completely before bread burns
Nutrition
- Serving Size: 1 sandwich
- Calories: 850
- Sugar: 12g
- Sodium: 1250mg
- Fat: 52g
- Saturated Fat: 24g
- Unsaturated Fat: 26g
- Trans Fat: 2g
- Carbohydrates: 48g
- Fiber: 3g
- Protein: 45g
- Cholesterol: 165mg