Clean and wash the spinach and drain well on a sieve. Peel and roughly dice the onions. Drain cheese and dice finely. Wash meat thoroughly and pat dry with kitchen paper.
Season with salt and pepper. Cover turkey breast with spinach, ham, onions and mozzarella. Roll up from the long side and tie together with thread. Place the roast on a fat pan, brush with oil and roast in a preheated oven (electric range: 175 °C/ gas: level 2) for approx. 1 1/2 hours.
Heat the stock. Add broth and wine little by little. In the meantime wash and peel the potatoes and cut them in half as desired. Peel the shallots. Peel garlic and chop finely. Mix potatoes, garlic and shallots and season with salt and pepper.
45 minutes before the end of the cooking time, place the potatoes, shallots and garlic on the baking tray and add to the cooking time. Wash the thyme, dab dry and pluck the leaves from the stems. 10 minutes before the end of the cooking time, sprinkle the roast and vegetables with thyme.
Clean, wash, quarter, seed and finely dice the tomato. Arrange roast and vegetables on a plate, sprinkled with tomatoes. Serve garnished with parsley and thyme.