Wild mushroom, tomato and zucchini gratin

1. In a medium saute pan, heat ¼ cup oil to smoking point.
2. Carefully add onions and saute until translucent.
3. Seasoni with salt and pepper to taste.
4. Remove from heat and transfer to a casserole dish.
5. Lay a single layer of tomatoes on top of the onions and sprinkle with half of the basil leaves.
6. Repeat with zucchini.
7. In a hot saute pan, saute the mushrooms in remaining olive oil until soft.
8. Add white wine, salt, and pepper.
9. Layer over zucchini.
10. Sprinkle bread crumbs evenly over top of mushrooms.
11. Repeat with parmesan and finish with remaining basil.
12. Bakei in a preheated 375°F oven for 30 minutes or until a golden crust has formed on the top. Remove from oven, cut into portions, and place on individual plates and serve.