Preheat oven to 375. Using half the butter, grease a pie plate and coat with bread crumbs.
Heat olive oil in large skillet. Add onion and garlic and saute for 10 minutes. Add dice dtomatoes and saute another 5 minutes. Raise heat to high; mix in zucchini, fennel seed, and salt and pepper to taste. Cook until zucchini is just tender (no more than five minutes).
Remove from heat and cool for five minutes.
Beat eggs. Stir in milk, then add the cooled zucchini mixture to it. Pour half the mixture into pie plate, layer all fo the Swiss cheese, then pour on remaining vegetable mixture. Sprinkle with Parmesan. Dab top with remaining butter.
Bake for 30 minutes, or until top is golden brown. Let stand five minutes before serving.