Pour the porcini mushrooms into a fine strainer and save the liquid to use later. If the liquid is sandy, let the sand settle, then carefully pour offf the liquid. Finely chop the porcini, discarding any pieces that are gritty or hard. Set aside.
Heat 1 tbls. of the olive oil in a saute pan and sear the white mushrooms over high heat with 1/4 teaspoons salt and a few grinds of pepper. As the mushrooms cook, they will release their juices; then the juices will evaporate and the mushrooms will begin to sear. At this point they'll begin to stick to the pan, but don't stir them. Cook over high heat until they're golden, then stir once and continue to sear for 1-2 minutes. Add the porcini soaking liquid to loosen the pan juices, then simmer for a few minutes, until the pan is nearly dry. Transfer to a bowl.
Heat the remaining tbls. of oil in the saute pan and add the leeks. Saute over medium heat with 1/4 teaspoons salt and a few grinds of pepper; when they begin to soften, in about 3 minutes, add the garlic and porcini mushrooms. Cover the pan and steam for 5-6 minutes, until leeks are tender. Add the wine to deglaze the pan, then simmer for a few minutes, until the pan is nearly dry. Add to the mushrooms, then set aside to cool. Season with salt and pepper to taste.
Preheat the oven to 500*F. Place dough on a lightly oiled pizza pan(or pizza stone); brush with olive oil. Spread the mushroom/leek mixture over the dough. Save a little of the Parmesan cheese to sprinkle on top after baking and toss the rest of the cheeses together. Sprinkle over the pizza.
Bake the pizza, in the pan for 8-12 minutes, until the crust is golden and crisp. Remove it from the oven and sprinkle on the remaining Parmesan.
This makes one 15" or two 9" pizzas.