Preheat oven to 350 degrees F (175 degrees C). Sprinkle the swiss cheese onto the bottom of the pie shell, and set aside.
Heat the olive oil in a skillet over medium heat. Stir in the onion and garlic, and cook until the onion has softened and turned translucent, about 5 minutes. Add the zucchini, tomatoes, and herbes de Provence, and cook 3 minutes more; season the mixture with salt and pepper to taste. Turn the heat to medium-low, cover, and cook until the vegetables are tender, about 20 minutes.
Spread the vegetable mixture into the pie shell over the shredded cheese, and flatten the top. Whisk together the eggs and milk, and pour over the vegetable mixture.
Bake in the preheated oven until the custard has set, about 20 minutes.