Heat olive oil in a large skillet and add the onion. Cook until just beginning to brown on the edges.
Add crumbled tofu and a pinch of black salt. Black salt gives the dish an eggy taste. If you don't have any just use regular salt. It'll be just as good.
Cook tofu until it has just begun to brown.
Add the Italian herbs, grated zucchini, and sliced mushrooms. Cook until the veggies are soft and most of their water has cooked away. Turn the heat off.
While the veggies are cooking, blend the silken tofu, water, nutritional yeast, cornstarch, tahini, garlic, turmeric, sea salt, and black pepper, and another pinch of black salt if using in a blender until smooth.
Pour the blender mixture into the skillet and combine.
Pour this mixture into the prepared pie plate and smooth the top.
Bake in a preheated 400 degree F oven for 25-30 minutes, until the center is set.