It's all about thick slices of tomato, lettuce, and onion -- dainty slivers would get lost in this mammoth sandwich.
Eighty percent lean ground beef chuck makes for a juicy but not greasy grilled burger. Form the patty loosely to ensure a tender texture (no slapping or patting), and make an indentation in the center to prevent doming.
Salt draws moisture out of meat. Generously season the outside of the patty rather than the meat mixture so the center stays juicy.
You need the sharpness of white cheddar to stand up to the beefiness of this burger. Add the cheese immediately after flipping to maximize melt.
A bakery roll, rather than a packaged bun, is worth it here; it will soak up the juice without getting gummy.