In a bowl gently mix together the ground beef, steak seasoning, and Worcestershire sauce. Split the meat mixture into 6 pieces.
Take one piece of the meat and split it into 2 pieces. Shape both pieces into thin flat rounds that are about the size of your buns or a little bigger.
Place about ¼ cup of shredded pepper jack cheese on top of one of the round patties. Carefully lift up the other patty, use a spatula if needed to avoid ripping any holes, and lay it on top of the cheese.
Thoroughly pinch the edges together to ensure none of the cheese will melt out. Carefully pat the burger down a bit so that it is flat and not mounded. Gently press a small indent into the middle of the top of the patty, this will help to keep the patty flat while cooking.
Very lightly season both sides of the patties with salt and pepper.
Repeat steps 3-6 until all of the patties have been shaped.
Heat a pan with 2 Tablespoons of oil over medium heat.
Cook 1-2 patties at a time (depending on the size of your pan). Cook the patties for 3-4 minutes on each side or until cooked through. You can use an instant read thermometer, the center of the burgers should be 140°F.
Once the patties are cooked, place onto your favorite hamburger bun and top with fresh arugula and crispy fried onions.
Serve immediately, or keep warm in a warm oven until ready to serve. Take caution when biting into the burgers as the cheese may be hot!