Heat oven to 375°F. In 12-inch skillet, melt butter over medium-high heat. Add zucchini and onions; cook 6 to 8 minutes, stirring occasionally, until tender. Stir in parsley flakes, salt, pepper, garlic powder, basil and oregano.
In large bowl, mix eggs and cheese. Add cooked vegetable mixture; stir gently to mix.
Separate dough into 8 triangles. Place in ungreased 10-inch glass pie plate, 12x8-inch (2-quart) glass baking dish or 11-inch quiche pan; press over bottom and up sides to form crust. Firmly press perforations to seal. Spread crust with mustard. Pour egg mixture evenly into crust-lined pie plate.
Bake 18 to 22 minutes or until knife inserted near center comes out clean. If necessary, cover edge of crust with strips of foil during last 10 minutes of baking to prevent excessive browning. Let stand 10 minutes before serving.