If using savory dough, prepare it.
Heat oven to 400°F
Place the oil in a skillet [note you can use water for this step if you want to reduce the fat] over med high heat. Add onion, leek, scallion, and ginger and sauté over medium heat until the veggies are limp. Add the vinegar and stir until evaporated.
Add the mushrooms and saute until they give up the liquid, approx 4 minutes. Remove from heat.
Process the tofu and sour cream until smooth. Blender or food processor, your choice. Turn into a large mixing bowl and add the mushroom mix with a slotted spoon then stir to blend.
If using savory dough, roll the dough on a 12 inch square of parchment paper into a 10 inch round. Pile the filling in the center and spread out leaving a two inch margin all around. Bring the dough up around the sides as if you were going to encase the filling but leave a 6 inch window. Crimp the dough around the sides to hold in place. Transfer to a baking sheet or a preheated stone. Bake until crust is golden brown and the filling is set, about 40 minutes. If the crust browns before the filling is set, cover with foil and continue to bake at 300°F for about 10 more minutes.
Notes: I personally found this needed a bit more spices. I used Lemon Pepper, Salt, Italian seasoning, a bit of wasabi powder, turmeric (made it a nice gold), and threw in some sliced tomatoes when I blended it. You want amounts? I will jiggle it some more and post corrections. Note I have a strong taste for strong tastes. This is fine with out it but if you like spice play around with it. Also I have used Ricotta cheese [no fat] in place of the sour cream. I have not tried with soy cheese yet.