Wash the potatoes thoroughly and cook for approx. 20 minutes. Peel and chop the onions. Rinse, clean and dice the zucchini. Wash, clean and dice the tomatoes.
Heat the oil, fry the minced meat in it until crumbly. Add onions and zucchini, sauté for approx. 5 minutes. Add tomato paste, salt, pepper, chili powder and stock, cook for approx. 10 minutes. Drain the potatoes, peel them, press them hot through the press. Mix with hot milk and butter, season with salt and pepper.
Crumble 2/3 of the cheese. Peel off the garlic cloves and press through the press into the puree. Fold in the crumbled cheese. Preheat the oven to 175 degrees (convection: 155 degrees). Add tomato paste to the minced meat, season to taste. Pour alternately with the mashed potatoes side by side in a greased baking dish. Dice the rest of the feta and sprinkle on top. Baked for 20-25 minutes.