Cut the tops of the tomatoes and peppers off and remove the interior.
If the zucchini is big, cut it in the middle.
Cut tops of the potatoes and remove the interior.
Remove the interior of the tomatoes, potatoes and zucchini and blend them in the food processor together with the tomato paste and the onion. Put the mixture in a bowl.Add the oil, lemon, the herbs, finely chopped, salt, pepper, oregano and the rice and mix well.The mixture should be slightly thin so if it is necessary add a bit of oil or water.
Stuff the vegetables, cover with the tops and put them in the pot in layers, the potatoes at the bottom then the peppers, the tomatoes and the zucchinis. But before layering your stuffed vegetables in the pot, cover its bottom with the stalks that you have saved.
Add water and cover the pot with a plate and its lid.Cook over low heat for about half an hour.
