6 tablespoons unsalted butter
2 onions, sliced 1-inch thick
1/4 cup, plus a splash of Powder Day IPA
1 pound ground beef
2 slices of cheddar cheese
2 slices of Swiss cheese
4 slices Rye bread
Salt and freshly ground black pepper, to season
Melt 2 tablespoons butter in a large skillet over medium heat. Add onions and season with salt and pepper. Cook onions for 20-25 minutes, stirring occasionally, until nicely caramelized.
Add 1/4 cup of Powder Day IPA, and lower heat to a simmer. Cook for 3-5 minutes. Remove from heat.
In a mixing bowl, add a splash of Powder Day IPA to ground beef. Mix in with fingers. Divide ground beef in half, then half again to make four equal-sized meat balls. On a cutting board, press each ball into a disc, then shape into patties, seasoning well on both sides.
Heat a large skillet over medium-high heat. Add patties and cook for 2-4 minutes, until nicely browned. Flip, top with cheese, and cook until cheese is melted, about 2-3 minutes.
Melt 2 tablespoons butter in a large skillet over medium heat. Add 2 slices of rye bread, top with two patties each, and caramelized onions. Top each with a slice of rye, cook for 3-5 minutes, until the bread is nicely browned, and flip patty melts over.
Add remaining butter, tossing sandwiches around in melted butter. Cook for 3-5 minutes, remove patty melts from the pan, slice, and serve.