Wash spinach if necessary (thaw frozen spinach). Peel tomatoes by placing them in a heatproof bowl and pouring boiling water over them. Let stand for about 3 minutes. Then the skin can be easily peeled off with a small knife. Dice tomatoes finely. Cut the carrot into large pieces.
Remove the mozzarella from the packaging and drain the canned, dried tomatoes slightly. Cut both into small pieces. Now mix the canned tomatoes with the mozzarella cubes.Peel the onion and garlic and cut them finely.
Heat some oil in a frying pan and fry the onion. Now add the spinach and garlic. If you are using thawed spinach, make sure it is well drained before adding it. Simmer everything together for a few minutes.
After cooling, mix the spinach mixture with the mozzarella mixture. Season with salt, pepper and nutmeg.
Season the inside of the prepared turkey roll roast with a little salt and pepper. Spread the filling evenly on the meat. Roll up the roast with a net or cooking twine. Now roll the turkey roll roast in breadcrumbs if desired.
Heat oil in a oven-proof pan or casserole. Brown the roll roast well on all sides. Then add the carrot pieces and the tomato cubes, fry briefly and then extinguish with white wine. Pour the heated broth over it.
Place the roll roast in the oven and roast it open for about 40 - 50 minutes. Occasionally pour the fond over it. Stick it briefly to check if it is done. No meat juice should come out anymore.
If it gets too dark but is not done, simply cover it with some aluminum foil and continue roasting.
Remove it from the oven and let it cool. Then strain the gravy or leave it chunky. Stir in cream or sour cream.
Remove the strings from the turkey roll roast and cut it into thick slices. Serve it with the sauce.