In a large bowl combine the onion, relish, soy sauce, and eggs. Add any of the optional ingredients you wish to use. Be sure to get the eggs mixed in completely.

Pat the meat out into 16 thin patties.

Spoon the pre-made filling mixture upon the top of eight of the patties. Place another patty on top. Press firmly to join them together to form a stack of 2 patties.

Wipe up any of the mixture that runs out of the patty stack and spread over the top of the patty stack.

These stacks can be grilled or broiled in your oven. Great served on a crunchy Kaiser roll.