- 12 ounces ground beef (preferably chuck)
- Kosher salt and freshly ground black pepper
- 2 tablespoons olive oil, divided
- 1 medium yellow onion, thinly sliced into half moons
- Small pinch red pepper flakes
- 1 tablespoon chopped fresh parsley leaves
- 4 slices rye bread
- 4 slices Swiss cheese
- 4 tablespoons butter, at room temperature
- Mustard, for serving
- Pickles, for serving
Generously season the beef with salt and pepper and form into 2 (1/2-inch thick) oval patties. Cook's Note: You want your patties thin and roughly the same size of the rye bread.
Set aside, or place in the refrigerator while you cook the onions.
Add 1 tablespoon olive oil into a large nonstick skillet over medium-high heat. Once oil is hot, add onion and saute until browned, about 8 minutes.
Season the onions with red pepper flakes, salt, pepper, and chopped parsley. Remove onions from the skillet to a bowl and reserve.
Add the remaining tablespoon oil to the hot skillet. Once hot, add the burgers and cook for 3 to 4 minutes until very browned on one side. Flip and continue cooking the other side for another 3 minutes. Remove from pan.
Preheat a grill pan to medium-high heat.
Assemble the patty melts:
Top 2 pieces rye bread each with a slice of cheese, onions, the burger patty, a second slice of cheese, and a final piece of bread.
Butter both the top and bottom of the sandwich.
Grill each sandwich until golden and the cheese melts, about 3 to4 minutes on each side.
Serve hot with mustard and a side of pickles.
Cook's Note: Ground chuck is cut from the shoulder, ranges from 15 to 20 percent fat, and has a rich flavor that is tender and moist. This is best choice for burgers.