Patty Melt

Ingredients

• 24 ounces onion – thinly sliced
• 6 tablespoons unsalted butter – divided, softened for spreading
• 8 slices rye bread
• 16 ounces ground beef (80/20)
• 1.25 teaspoons kosher salt
• 0.5 teaspoons black pepper – freshly ground
• 8 slices Swiss cheese

Instructions

1. Melt 2 tablespoons of the unsalted butter in a large skillet over medium-low heat. Add the onion and 0.25 teaspoon kosher salt, then cook, stirring occasionally, until deeply golden and jammy, 20–25 minutes; adjust heat to prevent scorching. Transfer onions to a bowl and wipe out the skillet.
2. Divide the ground beef into 4 equal portions and press into thin patties slightly larger than the bread slices. Season both sides of the patties with the remaining 1 teaspoon kosher salt and the black pepper.
3. Return the skillet (or a griddle) to medium-high heat. Cook the patties until well browned and just cooked through, 2–3 minutes per side (4–6 minutes total), or to an internal temperature of 155–160°F. Transfer to a plate and reduce heat to medium.
4. Spread the remaining 4 tablespoons softened butter evenly on one side of each slice of rye bread. Place 4 slices, buttered-side down, on a board. Top each with 1 slice Swiss cheese, a quarter of the caramelized onions, one patty, and another slice Swiss cheese. Close with remaining bread, buttered-side up.
5. Cook the sandwiches in the skillet over medium heat, pressing gently with a spatula, until the bread is deeply golden and the cheese is melted, 3–4 minutes per side; lower the heat as needed to prevent burning. Cut in half and serve hot.