Heat the clarified butter in a high, coated pan (I always use my wok) and fry the onions together with the garlic until golden yellow over a mild heat. Add all of the prepared vegetables (except the tomatoes !!), season with salt and cover and simmer over a mild heat for 15 minutes, stirring frequently.
Mix the milk with the cream and pour over the vegetables, mix well and simmer openly for another 25-30 minutes until the potatoes are cooked. The rest of the vegetables can still have a bit of bite. Finally fold in the tomatoes and diced feta and sprinkle with the parsley. Turn off the hotplate and cover and let stand for about 5 minutes until the feta has melted a little.
Season with salt and pepper and serve immediately.
Note:
The cooking time can vary a bit, depending on how thick the potato cubes were cut, they should be soft in any case!