In a frying pan with an ovenproof handle heat the oil and saute onion, garlic and green capsicum over a low heat. Saute until vegetables are just tender but not browned. Add the zucchini and continue cooking, stirring occasionally, until crisp-tender. Add the potatoes, stir well to combine and continue cooking, stirring frequently, until the potatoes are heated through and starting to stick to the pan.
Add the tomatoes and black olives, stirring well to combine with the other ingredients, and cook just until the tomatoes have begun giving up their juice.
Beat the eggs with the salt, pepper, oregano and cayenne. When all the vegetables are cooked, pour the eggs over them.
Arrange the tomato slices over the top of the eggs and sprinkle the mozzarella and parmesan cheeses over the tomato slices. Cook gently over low heat until the eggs are almost set (they'll be firm around the edges and a bit runny in the middle).
Slip the pan under the grill for a minute or two, until the eggs are fully set and the cheese has melted and begun to brown. Cut into wedges and serve.
I used 6 eggs and 1 cup of milk to pour over the vegetables in a casserole dish and then I cooked it in the oven. It served my husband and I plus our 8 year old and we had leftovers for another dinner. The vegies I used were broccolini, onion, garlic, grated carrot, tomato, kalamata olives and frozen peas. I only put parmesan on the top. - 27 Oct 2010