Preheat oven to 375 degrees. Line a 10 - inch ungreased pie plate with pie crust. Spread crust with mustard. Saute zucchini and onion using 1/4 cup butter or margarine for 2 minutes. Stir in parsley, salt, pepper, garlic powder, basil, and oregano. Saute mixture for an additional 2 minutes, or until vegetables are tender-crisp.
In a large bowl, beat eggs and cheese. Stir in vegetable mixture. Pour mixture into pie crust. Bake 20 to 25 minutes or until eggs are set. Let stand for 10 minutes before serving.