- Preheat oven to 350 degrees F. Grease a 3-quart rectangular or oval baking dish; set aside. In a small bowl cover tomatoes with boiling water. Let stand for 15 minutes; drain. Chop tomatoes; set aside.
- Meanwhile, in a large skillet cook and stir onion and garlic in the 2 tablespoons hot butter over medium heat about 4 minutes or until tender. Add zucchini; cook and stir for 2 minutes more. Stir in corn and chopped tomatoes; set aside.
- In a large bowl whisk together eggs and milk. Gradually whisk in cornmeal. Whisk in ricotta cheese, Italian seasoning, salt, and pepper. Stir in the corn mixture and Parmesan cheese. Carefully pour into prepared baking dish (dish will be full).
- Bake for 20 minutes. Meanwhile, in a small bowl toss together panko and the 1 tablespoon melted butter. Sprinkle over top of corn mixture. Bake about 30 minutes more or until the top is brown and a knife inserted into the center comes out clean. If desired, garnish with parsley.
Prepare as directed, except do not preheat oven and cool zucchini mixture to room temperature after Step 2. Once cool, continue with Step 3 and pour mixture into prepared baking dish. Cover tightly with foil; chill for up to 24 hours. Stir corn mixture before baking. Bake and top as directed in Step 4.