Divide ground beef into four quarters and roll them into balls.

Meanwhile, get a large cast iron skillet or flat top griddle super, smoking hot.

Once the surface begins to smoke, add the beef balls and top each one with a hefty pinch of salt, fresh cracked pepper, 1 teaspoon of burger sauce and equal parts sliced onion. Place a sheet of wax or parchment paper on top of each burger (to avoid it sticking to the spatula) and smash the burger down using a thin metal spatula and something heavy like a sandwich press or a meat mallet.

Once the burgers look like they’re caramelizing and about 60% cooked through, flip them, scraping up any bits that might be sticking to the cooktop.

Once flipped, top each of the smash burgers with 2 slices of American cheese and let that start to melt. The burgers are done when they reach 165F degrees.

Turn the heat to low and smear 1 tablespoon of the burger sauce onto four slices of bread.

Melt half of the butter on the other clean side of the skillet or cooktop (making sure there are no burnt bits or anything sticking to it) and place those four bread slices, sauce side up. Flip the cheeseburgers onto the sauced bread - cheese side down - then top with a few slices of pickles then evenly distribute the shredded havarti over it. Place the other slice of bread on top and use the remaining butter to butter them.

Once the bottom half of the sandwich is cooked to golden brown and most of the cheese has melted, flip it and continue cooking until the remaining side is golden brown and the remaining cheese has completely melted.

Remove from heat and let rest 1 minute before serving. Serve with remaining smash burger sauce for dunking.