Cook zucchini and onions in butter until tender. Stir in parsley and seasoning. In large bowl, blend eggs and cheese. Stir in vegetable mixture. Separate dough and line pan. Spread mustard on crust. Pour mixture into crust. Bake 375° for 20 - 25 minutes or until knife comes out clean. If crust gets too brown, cover with foil last 10 minutes.