Preheat the oven to 350 degrees. Prick holes in the pie crust dough all over the bottom and sides of the pie shell. Bake until a light golden color, 20 to 25 minutes. Let cool. Put the tofu, rice vinegar, onion powder salt and mustard in a blender and blend until smooth. Transfer to a large bowl. Heat the oil in a large frying pan over mediumheat. Add the onion, garlic, mushrooms, and tamari and cook until the mushrooms are browned, about 6 minutes. Add the spinach, cover and cook until the spinach is wilted, 2 to 3 minutes. Uncover and cook, stirring oftnem, until the excess moisture has evaporated, about 3 minutes. Add to the tofu mixture, along with the basil, and stir to mix. Pour into the baked pie crust. Arrange the tomato slices, overlapping in a cirlce, on top. Bake until the top is lightly browned and the filling seems firm in the center, 40 to 50 minutes. Let cool 15 minutes. Serve warm or at room temperature. From DEEANNE's recipe files