Cook the rice and wait for it to cool off. Fry grated carrots and onions on butter, wait for it to cool off. Mix minced meat with spices (salt and pepper too), fried onions and carrots, rice and mayonnaise. Form meatballs from the mass. They should be about the size of an egg.
Sauce: Mix tomato sauce with sour cream, mayonnaise, and flour. Pour a bit of water while thoroughly mixing, add spice herbs. Pour some sauce on the cooking pan, and place the meatballs on it. Pour the rest of the sauce on top. 2/3 of the meatballs should be submerged in the sauce.
Cover it with a lid or foil and bake at 200 C for about 50 minutes. Enjoy with potatoes or vegetables.