For the zucchini casserole, cut the zucchini into sticks. Peel the onion and chop finely. Heat the oil in a pan and brown the onion.
Add the ham and the zucchini and sauté briefly. Season with salt and pepper.
Pour the mixture into a greased pan and cover with tomato slices and sprinkle with grated cheese.
Bake in the oven at 200°C for about 15 minutes. Serve the zucchini casserole.