Soak rolls in cold water. Peel and finely chop the onions. Knead the minced meat, squeezed out roll, half of the onions, egg, mustard, salt, pepper and paprika with the dough hooks of the hand mixer.
Form dumplings from the minced meat. Put rice into 400 ml boiling salted water and simmer for about 18 minutes. Heat oil in a pan. Fry the minced meatballs for about 12 minutes at medium heat, turning them over.
Meanwhile peel and finely chop the garlic. Clean and wash the leek and cut into rings. Take the meatballs out of the pan and put them aside. Put the rest of the onions, garlic and leek into the frying fat of the meatballs and fry over medium heat, turning them over.
Stir in tomato paste, add tomatoes, bring to the boil and simmer for about 5 minutes. Season to taste with salt, pepper, paprika, sugar and cayenne pepper. Add corn and meatballs. Bring to the boil again briefly.
Wash parsley, dab dry and chop finely. Arrange rice sprinkled with paprika and meatballs in tomato sauce sprinkled with parsley on plates. Garnish with parsley as desired.