Soak bread crumbs in milk until softened.
Add onion to 1 tablespoon butter in small saucepan and cook slowly 3 minutes.
Mix softened bread, cooked onion and meat.
Add eggs, salt, pepper, nutmeg and paprika.
Mix thoroughly until very smooth and light.
Shape meat into small balls, dusting the hands with flour while shaping the balls.
Melt remaining 3 tablespoons butter in large frying pan.
Add meat balls and fry until golden brown all over.
Remove from pan and add meat extract and 3 tablespoons flour.
Stir untl well blended.
Add water and a few grains of pepper.
Cook, stirring constantly until thickened.
Reduce heat very low and cook 5 minutes.
Stir in sour cream, a rounded tablespoon at a time, stirring until thoroughly blended after each addition of sour cream.
Return meat balls to gravy, cover pan and simer very gently 10 minutes.
Serve in deep casserole.
Sprinkle with minced parsley.