Heat the oil in a strong earthenware casserole dish and sauté the onion, garlic and green pepper for about 5 mins, then add the eggplant and continue frying for another 5 mins over a low heat.

Add tomatoes and zucchini, season with salt and pepper and add the oregano - cover and continue frying for a further 15 mins over a medium to low heat.

Remove from the heat when the vegetables are well cooked - can be served hot or cold.