In a mixing bowl, combine the ground beef, salt, and pepper.

Shape the beef mixture into 4 equal patties.

Heat a skillet or griddle over medium-high heat.

Place a slice of cheese on each patty during the last minute of cooking.

Lightly toast the hamburger buns in the skillet until golden brown.

In a bowl, mix together mayonnaise, ketchup, and mustard.

Spread the sauce on the bottom half of each bun, layer on the patty, chopped onions, and pickles.

Top with the other half of the bun and serve immediately.