Around 1/2 a finely chopped small brown onion, 5/600 grms mince and LOTS of fine salt, not the stuff you grind, mixed well, then left for at least a few hours before cooking. The salt 'binds' the burger, and stops it from falling apart, as well as improving the taste, and for the "health conscious, use iodised salt".
Make them a good size, as they shrink a fair bit. Takes a while to perfect, but meat should end up at least the size of the roll, if not bigger.
For ease of cooking, I make them between two sheets of baking paper, flatten them out well, then cut paper. to suit the fry pan size, and cook in a dry pan. For a good burger, don't use just premium' mince, as there isn't enough fat, and your burger will be tasteless. A burger with around 1 part premium mince, 1 part regular mince, and 1 part sausage mince is even better. Once it has cooked for a while, flip, remove first piece of baking paper, and remove second one next time you turn.
A burger doesn't need egg, bacon, pineapple or cheese. Even sauce is a waste. A very well toasted roll, lots of butter, (not marg), DRY fresh 'torn' lettuce, beetroot, (WELL drained) on paper towel, tomato with salt and pepper, (if you need tom. sauce, add to tomato, it brings the flavour out), then the meat, topped with the other 1/2 of well toasted and buttered roll.
Stack in this order, it does make a difference, and at the end of the day, a burger with just meat and lettuce is just as good, if not better.
Recently found another long, flat electric grill, which I bought, soley for making burgers! (home maker brand, about $29 at K-mart. Works well, and heaven forbid, would also be perfect for cooking steaks, chops and snags.
Very low sides, and the small addition at the front is a slide out oil catcher.
