Creating Smash Burgers with House Sauce is simple when you follow these steps:

1. Prepare the House Sauce: In a bowl, combine mayonnaise, ketchup, Dijon mustard, pickle relish, garlic powder, onion powder, salt, and pepper. Mix well and set aside.
2. Preheat the Griddle: Heat a flat griddle or skillet over medium-high heat until hot.
3. Shape the Beef: Divide the ground beef into four equal portions (about 4 ounces each). Gently shape them into balls; do not overwork the meat.
4. Smash the Patties: Place the beef balls on the hot griddle. Using a spatula, smash each ball down to about ½ inch thick. Season with salt and pepper.
5. Cook the Patties: Cook for about 3-4 minutes until a crust forms on the bottom. Flip the patties and place shredded cheese on top. Cook for an additional 2 minutes until the cheese melts.
6. Toast the Buns: While the patties are cooking, split the hamburger buns and toast them on the griddle until golden brown.
7. Assemble the Burgers: Spread the house sauce on the bottom bun. Layer with the cooked patty, shredded lettuce, tomato slices, and red onion. Top with the other half of the bun.
8. Serve Immediately: Enjoy your delicious Smash Burgers while they’re hot!