Wash the meat and dab dry. Peel garlic. Rub meat with garlic, salt and pepper. Place on a fat pan of the oven and cook in the preheated oven (electric cooker: 175 °C/ circulating air: 150 °C/ gas: level 2) for about 2 1/2 hours.
Gradually add 1/2 litre of water. Peel, wash and dice the potatoes. Distribute around the roast about 30 minutes before the end of the cooking time. Drain tomatoes and cut into pieces.
Wash the rosemary, remove the needles from the branch. Clean, wash and chop the spring onions. About 10 minutes before the end of the cooking time add the spring onions, tomatoes and rosemary to the potatoes. Season with salt and pepper.
Mix the curd and sour cream. Wash the herbs, dab dry, pluck the leaves from the stalks and cut them into small pieces. Stir into the quark, season with salt and pepper. Arrange roast and Italian potatoes on a plate.
Add the quark.