Place potato in a small saucepan and cover with water. Bring to a boil. Reduce heat; cover and cook until tender, 10-15 minutes. Drain., In a large skillet, saute the onion, cinnamon, bay leaf and cloves in oil until onion is tender. Add the chicken, garlic, curry and ginger; cook and stir 1 minute longer. Stir in the tomatoes, salt and potato., Cover and cook until chicken is no longer pink, 10-15 minutes. Remove from the heat; discard cinnamon, bay leaf and cloves. Stir in sour cream. Serve with rice.