Preheat oven to 350° F. Coat a 9-inch round pie plate with cooking spray. Set aside.
Pierce potatoes with a fork. Microwave on HIGH for 7 to 8 minutes or until soft. Remove from microwave and let cool 5 minutes.
Combine zucchini, broccoli, red bell pepper, carrot, green onion, garlic powder and 1/2 teaspoon salt in a microwave-safe bowl. Microwave on HIGH for 5 to 6 minutes or until vegetables are tender. Set aside.
Slice cooked potatoes into thin slices. Arrange slices in prepared pie plate along the bottom and edges of plate, creating a "crust". Drizzle olive oil and sprinkle Herbes de Provence over the potatoes. Add vegetables into the potato crust. Sprinkle cheeses over the vegetables.
Whisk the egg whites, eggs, fat-free half and half and remaining 1/4 teaspoon sea salt in a small bowl until well combined. Pour over the top of the cheeses.
Bake at 350° F for 45 minutes or until set. Remove from oven and let cool for 5 minutes before slicing and serving.