Dice the feta, then knead a meat dough from the mince, breadcrumbs, egg and feta. It should be relatively firm, if necessary add breadcrumbs. Season with salt, pepper and plenty of oregano.
Dice the onion, finely chop or press the garlic. Scald the tomatoes briefly and then peel them, remove the seeds and dice. Halve the zucchini lengthways and scoop out with a spoon. You may need a zucchini more or less, it depends a lot on the size. Cut large zucchini in half crosswise, then lengthways. Preheat oven to 200 degrees.
Sauté the onion and garlic in olive oil, then add the diced tomatoes and sugar. Season with thyme, plenty of basil, salt and pepper.
Put the tomato mixture in a roasting pan or casserole dish, fill the zucchini halves with the minced mixture and place on top of the tomatoes. Bake in the oven for about 30 to 45 minutes.