- Heat grill to high. Preheat oven to 425° F.
- Cook the bacon till crisp and set aside. Once cooled, chop it.
- Brush bacon grease (or olive oil) on squash and onions. Lay on the grill and cook until brown and tender, turning and moving with tongs. (The onion might fall apart; just try to brown it a little.)
- Use a little more bacon fat or olive oil to grease a 9- by 9-inch baking pan. Heat oven to 350° F. Layer half the squash in the bottom. Chop the onion and scatter half on top of the squash. Slice tomatoes and put half of them on top of the onion. Sprinkle with half the salt and pepper, bacon bits, cheese and crumbs. Repeat layers. Drizzle with remaining bacon fat and enough olive oil to make 2 tablespoons.
- Place in oven and bake uncovered for 45 minutes (baking can also happen in a covered grill, but the pan will turn black). Allow to stand 10 minutes before serving. Serve with a slotted spoon.