Those of you with recipes that call for ketchup in the recipe have got a FAKE recipe. Maid-Rite has NEVER added ketchup to their meat for their classic burger while cooking it. The secret is twice-ground ground beef (probably the cheapest you can find - it is often told that the beef has other things ground into it, such as kidneys and hearts). The meat is very, very fine.
1 1/2 pounds ground beef, twice ground
1 medium onion, minced
1 can chicken broth
Salt and pepper
Crumble meat in a skillet over medium heat, then add onion. Brown meat and cook until onion begins to turn clear. Drain off fat. Meat should be very crumbly. Add broth and cook, stirring constantly, until the liquid evaporates. Season with salt and pepper.
Serve on buns with slices of dill pickle. Add mustard, if desired.