Preheat a flat-top griddle, grill griddle, or large skillet over medium-high to high heat.

Place the ground beef in a large bowl. Add the diced onion, salt, and black pepper.

Cut four squares of parchment paper large enough to cover each portion of meat.

Gently mix the ground beef mixture, then divide it into four equal portions. Roll each portion into a quarter-pound ball.

Place the ground beef balls onto the hot cooking surface. Set a square of parchment over each ball and use a burger press or sturdy spatula to smash the meat into a thin patty.

Remove and discard the parchment paper.

Cook the burgers for 1–3 minutes per side, depending on thickness and preferred doneness.

After flipping, place a slice of cheese over each burger and let it melt as the burgers finish cooking.

Drizzle barbecue sauce over each burger.

Transfer to toasted sesame seed buns and finish with your favorite burger toppings. Serve hot.