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