Divide ground beef into four ounce portions.
Press the ground beef onto a flour tortilla in a thin layer, pressing it out to the edges of the tortilla.
Season beef generously with salt and pepper.
Heat a non-stick skillet on the stove over medium heat.
Add butter, lard or oil to the pan, and swirl to coat the bottom of the pan.
Place a tortilla, beef side down in the skillet.
Cook for 2-3 minutes until beef is browned, pressing down on the tortilla with a spatula as the beef cooks to ensure the beef sticks to the tortilla.
Once the beef patty is browned, flip the tortilla over.
Top beef with two slices of American cheese and place a lid over the top.
Cook for 1-2 minutes, just to crisp the flour tortilla, make sure the beef is cooked through and the cheese is melty.
Remove from heat with a spatula.
Top with some special sauce, minced onion, sliced pickles, and shredded lettuce.
Fold tortilla in half to serve.
Serve with additional sauce on the side.