Chop tomatoes. Peel onions and garlic and chop finely. Put minced onions, half of the onions and garlic, herbs, mustard, 1 1/2 tsp salt, 1 1/2 tsp pepper, yoghurt and egg into a mixing bowl. Knead well with the dough hooks of the hand mixer
Drain and dice the mozzarella. Put the chopping mass on a piece of foil and press it with your hands to a chopping plate (approx. 24 x 24 cm). Spread the mozzarella evenly on the plate, leave a rim of approx. 2 cm all around
Roll up the chopped mass with the help of the foil. Form into a loaf again with your hands. Score the surface several times with a knife. Place on a baking tray lined with baking paper and bake in a preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: see manufacturer) for approx. 1 hour
In the meantime, heat oil for the sauce in a pot, sauté the remaining onions and garlic in it. Sprinkle with sugar, add tomato paste, sauté briefly. Season with salt, pepper and paprika. Deglaze with tomatoes. Bring to the boil and simmer for about 10 minutes. Season again with salt, pepper and paprika. Keep warm
Clean, wash and drain the rocket well. Leave ham hot in a pan without fat, remove. Remove meat from the oven. Arrange on a plate with Parma ham and rocket. Add the sauce