Remove from pan and reserve 2 tablespoon of bacon grease.
Mix the ground beef, steak seasoning, caramelized onions, panko and bacon grease in a bowl (just until combined as I didn’t want to overwork the meat).
Shape into 4 patties and indent one side (this prevents them from rounding up).
Cover and chill for 30 minutes.
Preheat skillet over medium heat.
Drizzle just a trace bit of oil in the pan.
Place the patties and do not move for 5-6 minutes.
Flip when the bottom has a caramelized brown crust.
Cook for another 3-5 minutes (or until desired done-ness).
In the last minute of cooking add the Jarlsberg cheese on top and cover with a lid (this helps melts the cheese).