Roughly chop the tofu, wrap it in a double layer of paper towel (or clean teatowel), and put it on a plate with something heavy on it to help it expel moisture.
Squeeze out the water from the soaked shitake mushrooms and finely dice the tops- leave the stems out as they tend to be too woody.
Finely dice the chestnut mushrooms
Combine all the ingredients except the panko breadcrumbs in a bowl and mix to combine.
Add a bit of the water that the shitake mushrooms were soaked in if the mix is a bit dry.
Squish together palm sized burger patties, rolling them in the panko breadcrumbs
Gently pan fry the burgers - about 5 mins each side.
Serve on a bun, or a lettuce leaf with salad and the condiments of your choice.
Notes
I really love eating these with Layu (or Rayu)- a Japanese condiment made from chillis, grilled garlic and sesame oil... and maybe a little mayo. Yum!