Add tamari, mirin, and sugar to a small bowl. Heat in a microwave for about 30 seconds to dissolve the sugar. Whisk. Set aside.
In a separate small bowl add tapioca flour and water. Whisk. Set aside.
Drain and press the tofu. If you don't have a tofu press, you can place tofu in between a clean kitchen towel with a heavy object on top.
Heat olive oil in a large pan. Add sliced tofu. Cook until golden.
Add the teriyaki sauce and the tapioca flour mixture to the pan. Simmer until the sauce thickens.
On a slice of toasted bread, add tofu and teriyaki sauce, then spicy raw sauerkraut. Top with another slice of bread. Serve with a side of spicy thousand island dressing (or spread on top layer of bread). Repeat with the rest of sandwiches.
Notes
Store tofu and sauce in an airtight container for up to 5 days.Store spicy Thousand Island for up to 10 days. See the package on the raw sauerkraut for how long it lasts.I don't recommend storing assembled sandwiches because they can get soggy.When I originally published this recipe I used 12 ounces of store-bought vegan chicken. The brand I used doesn't sell it anymore, so I used tofu when I republished this recipe.