Peel the tomato and dice it.
Peel the tomato (blanch) is very simple. You have to put it in boiling water for one minute. After that, the peel is removed very easily.
Sauté/simmer/ fry onions until transparent. Add tomatoes and stew under the lid for five minutes.
Meanwhile, cut the zucchini and eggplant into a small cube.
Send them to the tomatoes and onions.
Simmer the vegetables first, under cover, and when to stand out a lot of moisture, without a lid to evaporate excess moisture, which further interfere with normal grilled tortilla.
Vegetables should be "al dente", that is, they should be a little ready in our understanding, plump but not soggy.
Salt the vegetables to taste. Leave to cool.
Boil potatoes in salted water and cut into cubes.
More often potatoes cut into a cube and fry it. If you have nothing against fried food, fry the potatoes.
Beat eggs with grated cheese.
Add potatoes and vegetables. Stir and try for salt. Season with spices to taste.
Put the mixture in a greased and sprinkled form and send in a preheated 200 degree oven for about 20-25 minutes (focus on your oven, the top should be browned, and the egg mixture is baked).