Heat the butter and sauté the onions and carrots in it. Sprinkle with flour and curry and sweat. Pour in 1/2 l water, stir in the broth and simmer for 15 minutes.
Squeeze out the bun well. Mix the mince, egg and bread roll and season with salt and pepper. Shape the mixture into small balls and fry in the heated oil for approx. 5 - 7 minutes.
Stir the crème fraîche into the vegetables and season with salt and pepper. Put the meatballs in the sauce, heat them up and sprinkle with parsley.