Preheat a grill with a medium-high heat for direct heat cooking.
Make a slight indentation in the center of each Rocket patty.
Brush the grill grate with oil. Evenly space the burgers on the grill and cook, turning once, until grill marks appear, 4 to 6 minutes total for medium. (Resist the urge to press down on the burger with a spatula as they cook.) Remove burgers from grill and let rest 1 to 2 minutes.
Brush cut side of buns lightly with oil and grill cut-side down until light golden brown, if desired. Put a burger on the bottom of each bun and top with lettuce, tomato, onion, ketchup, mustard, pickles and bun top. Serve with potato chips on the side, if desired