Ingredients
Scale
- 1/2 lb Ground Beef (80/20 lean-to-fat ratio is essential)
- 4 slices Rye or Sourdough bread
- 4 slices Swiss or American cheese (or both!)
- 1 large Yellow Onion, thinly sliced
- 2 tbsp Unsalted Butter
- 1 tbsp Neutral Oil (like avocado or vegetable oil)
- Kosher salt and cracked black pepper to taste
- Secret Sauce: 2 tbsp Mayonnaise, 1 tbsp Ketchup, 1 tsp Yellow Mustard, 1 tsp Dill Pickle Juice
Instructions
- Step 1: Caramelize the Onions and Prep Sauce: Start by melting one tablespoon of butter in a skillet over medium heat. Add your thinly sliced onions and a pinch of salt. Cook them slowly, stirring occasionally, until they are deep golden brown and soft. This should take about 10–12 minutes. While the onions cook, whisk together your mayonnaise, ketchup, mustard, and pickle juice in a small bowl. Set the sauce and onions aside.
- Step 2: Portion the Beef: Divide your ground beef into four equal portions, roughly 2 ounces each. Roll them into loose balls. Do not overwork the meat or pack it tightly; you want the edges to be able to spread out and get crispy when you smash them. Keep the beef cold until the very moment it hits the pan to ensure the fat doesn’t melt prematurely.
- Step 3: The Smash and Sear: Wipe out your skillet or use a flat-top griddle. Heat it over high heat until it is smoking slightly. Add a tiny drop of oil. Place two beef balls into the pan. Immediately use a heavy spatula or a burger press to smash them down until they are paper-thin. Use a piece of parchment paper between the press and the meat to prevent sticking. Season generously with salt and pepper. Sear for 2 minutes until the edges are dark brown and lacy. Flip the patties, add a slice of cheese to each, and cook for another 30 seconds.
- Step 4: Assembly and Final Toast: Butter the outside of your bread slices. Place one slice of bread in a clean pan over medium heat. Spread a layer of sauce on the bread, then stack two crispy patties, a generous portion of caramelized onions, and the second slice of bread. Grill the sandwich until the bread is golden brown and the cheese is fully melted, flipping once. Repeat for the second sandwich.
- Cook Time: 25 minutes