Parboil the potatoes in a saucepan of lightly salted boiling water for 5 minutes. Drain and set aside.
Heat the oil in a large, deep frying pan and fry the onion and garlic over a medium heat for 2–3 minutes to soften. Add the capsicums and zucchini and fry, stirring occasionally, for a further 10 minutes.
Add the potatoes and tomatoes and continue cooking, stirring occasionally, for 6–8 minutes or until all the vegetables are tender.
Stir in the oregano and season to taste with salt and pepper. Make four hollows in the vegetable mixture and break an egg into each hollow. Cover the pan with a lid or a baking tray, and cook for 8–10 minutes or until the egg whites are set. Serve immediately while piping hot.