These are just patties made of a pack of drained and pressed tofu mashed with a fork and mixed with
beni-shoga (pickled red ginger)
chopped spring onions
chopped reconstituted dried mushrooms
1 large egg
1 tablespoon sake
dash of mirin and soy sauce
generous pinch of salt
Spoon out portions and fry in a wide pan for a couple of minutes before turning, then remove from the heat and drain on kitchen paper.
The lunch box is made of a layer of brown rice, and lightly pickled cucumber and radishes.
The other compartment is just a plastic wrapped bottle filled with sudachi flavoured ponzu sauce. (These burgers are also good with Thai sweet chili sauce.)