01 -
Take each rye bread slice and generously butter just one side. Put them aside for now.
02 -
Toss the beef with the salt, pepper, and onion powder. Shape everything into three patties that fit your bread size.
03 -
Heat a skillet on medium-high and sear patties for a couple of minutes on each side. Lower the heat to medium-low and let them cook through until no pink remains, or they measure 160°F (71°C) inside.
04 -
While the meat cooks, mix up the mayo, bacon bits, ketchup, sugar, and relish in a bowl. Stir until it all comes together smoothly.
05 -
Warm another skillet over medium heat. Lay down a slice of bread, buttered side touching the pan. Stack two slices of cheddar, one cooked patty, and two slices of Provolone. Spread sauce on the plain side of a second bread slice and stick that sauce-side down on top.
06 -
Toast the sandwich for about 2 or 3 minutes per side until the bread’s golden and the cheese oozes. Repeat until you’ve made all three sandwiches.