Wash the tomatoes and cut off a lid. Hollow out the tomatoes, put the inside aside. Peel and finely chop the onion. Heat oil in a pan. Fry the minced meat in it until crumbly. Add onion, 1 tablespoon of tomato paste and tomato interior, season with salt, pepper and dried basil.
Simmer for about 5 minutes. Fill the tomatoes with the minced meat mixture, place in an ovenproof dish and pour in the stock. Cook in the preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) for about 20 minutes.
Place the lid in the casserole dish if necessary. Cut the mozzarella into cubes and sprinkle over the tomatoes 5 minutes before the end of cooking time. Take the tomatoes out of the casserole dish and pour the liquid into a pot.
Put the tomatoes back into the tin and keep warm. Add the aiwar, 1 tablespoon of tomato paste and cream to the liquid, bring to the boil. Bind with sauce thickener. Pour the sauce back into the tomatoes. Wash basil, dab dry and cut into strips.
Sprinkle over the tomatoes. Pea rice tastes good with it.