Chicken hearts cooking itself doesnt take much time - it takes their preparing. A membrane department, venticles cleaning and deferents cutting of 1 kg of hearts may take about 40-60 minutes. But this dish worths that!
For chicken hearts with sour cream you need
1 kg of chicken hearts
4 onions of middle size
2-3 full tablespoons of sour cream
spices
2 full teaspoons of flour
