For the filling, peel, wash and cut carrots into small slices. Cook in boiling salted water for about 5 minutes. Drain. Clean, wash and cut 100 g leek into rings.
Stir curd cheese, 2 teaspoons mustard and egg yolk until smooth. Season with salt and pepper. Fold in prepared vegetables. Wash the meat and dab dry. Cut a pocket into it and fill it with the prepared mixture.
Plug with wooden sticks and wrap them tightly with kitchen string. Place the roast on the fat pan of the oven. Cook in the preheated oven (electric cooker: 200 °C/ gas: level 3) for about 1 1/4 hour.
Clean, wash and cut the soup greens into large pieces. Arrange around the roast. Pour 1/2 litre of water over it. For the vegetables, peel and halve the potatoes and cook them in boiling salted water for about 20 minutes.
Clean, wash and cut the rest of the leek into small pieces. Clean, wash and slice the tomatoes. Heat oil in a pan just before serving. Brown the leek in it. Deglaze with broth and steam for about 5 minutes.
Add the tomatoes. Season with salt and pepper. Fold in potatoes. Take turkey out of the oven and keep warm. For the sauce, pour the roast stock through a sieve. Add cream and bring to the boil. Stir in sauce thickener, bring to the boil again.
Season to taste with salt, pepper and remaining mustard. Arrange the roast with the vegetables and some sauce on a plate. Serve garnished with parsley. Add remaining sauce extra.