Combine ground sirloin, seasoned salt, and ground pepper. Mix well. Slice onion thinly and place into a skillet with peanut oil. Grill onions slowly, do not brown onions. When the onions are almost translucent make 6 to 8 hamburger patties, make them thick (approximately 1/2 inch), and place into hot pan.
Grill hamburgers for 4 to 5 minutes before turning them. Flip hamburgers, and remove onions. When hamburger patties are done assemble them with. Bottom bun, pickle, meat patty, cheese, grilled onions, and then ketchup. Serve quickly. We imagine you will find these tasty.