Place a large cast iron skillet over medium-high heat and add ground beef and onions. Cook stirring with a wooden spoon until meat is browned.
Add garlic and Worcestershire sauce, stir and cook for 1 more minute.
Drain any grease.
Next, add Thousand Island Dressing, also add salt, and pepper. Stir to combine.
In a small bowl, combine cornstarch and beef broth until the cornstarch is fully dissolved.
Add the broth slurry to the pan and stir until thickened, 1-2 minutes.
To serve, place a cheese slice on the bottom bun and then some of the meat mixture, top with the bottom bun of another set of buns, and then add more meat mixture. Add another slice of cheese.
Add the toppings: shredded lettuce, pickles, and Thousand Island Dressing.