Preheat a clean barbecue grill on high.
Toast both halves of the bun, face down, in a skillet over medium heat.
Set aside.
Cut each of the 2 onion rings into quarters.
Mix the catsup and relish together.
This is your “secret sauce.”
Form the ground beef into a thin patty slightly larger than the bun.
Grill the meat for 2 or 3 minutes per side.
Salt slightly.
Build the burger in the following stacking order from the bottom up: bottom bun, half of the mayonnaise, pickles, lettuce, tomato slices, onion, beef patty, remainder of mayonnaise, special sauce (catsup and relish), top bun.