Heat a large skillet over medium heat. Place the butter in the skillet and swirl it around. Place the hamburger buns cut-side down in the melted butter and toast for about 60 seconds. Remove the buns from the skillet.

Form the ground chuck into 4 patties and place them in the skillet. Use a spatula to press down on the hamburger patties. Then take a large soup can that has been wrapped in aluminum foil and press each meat patty down onto the skillet. Cook for about 3 to 5 minutes on each side, seasoning each side with salt and pepper while cooking. Top each patty with a slice of cheese.

To assemble the burgers, place the mustard on the bottom bun, followed by the pickles, shredded lettuce, tomatoes, and red onions. Add the burger patty and cover with the top bun. Serve immediately.