1. Preheat oven to 350 degrees Fahrenheit.
2. Cook zucchini in water to cover for 15 to 20 minutes in a medium-size pot. Drain.
3. Sauté onions and mushrooms in oil until onions are golden and soft. Combine all ingredients, including the zucchini and sautéed vegetables, and mix well.
4. Place the mixture into the two pie crusts and bake, uncovered, for one hour.