Trim ends off onions, peel, then slice thin. Melt 1 Tablespoon butter in skillet. Cook onions slices on medium heat for 20-25 minutes, stirring occasionally. When done, the caramelized onions should be softened and light brown. Set aside.

Season ground beef with salt, pepper, garlic powder and Worchestershire sauce. Mix well. Shape meat into 4 slightly oblong patties (to fit shape of rye bread). Grill beef patties on grill or in skillet on medium-high heat (spray skillet with non-stick spray or use melted butter) until cooked through to your preferred done-ness. Make sure the grill or pan you use is very hot before adding the meat. This helps to create a quick, crusty "sear" on the outside. When done, set beef patties on paper towel to drain excess grease.

When ready to cook sandwich, spread butter on one side of each slice of bread. Place cooked meat patty onto the non-buttered side, then piled on the caramelized onions. Top with slice of Swiss cheese. NOTE: If you want a LOT of cheese, place a piece of Swiss cheese on the bread before placing the patty on, then add another slice to the top.

Place a slice of buttered bread on top of the cheese (butter side out). If you wish to add Thousand Island dressing, spread it onto the unbuttered side of the top slice of bread. Cook patty melt on low heat as you would a grilled cheese sandwich. Once the bottom is golden brown and toasty, carefully flip the sandwich (with a spatula) to the other side, and continue cooking until golden brown, cheese has melted, and sandwich is heated through. Once done, carefully slice patty melt in half, and serve with additional Thousand Island dressing or ketchup for dunking! Enjoy!