Wash and peel the potatoes, the eggplants, and the zucchini and finely dice them.
In a wide pan, heat some olive oil and fry the potatoes, eggplants, zucchini and sausages until they are well cooked. Remove them with a slotted spoon and leave them on a paper towel in order for the excess oil to be soaked up.
In a baking tray lined with grease paper, place the fried vegetables, sausage, cheese and pour over with eggs. Mix well, sprinkle with salt and pepper and bake the omelet in the oven at 200°C for about 15 minutes.