In large saucepan heat 2 tsp oil over medium heat. Add half of the chicken and cook 3 minutes until brown. Remove from pan and set aside. Repeat with remaining chicken.
Add remaining oil to pan; add garlic, onion, and ginger. Reduce heat to medium and cook, stirring constantly for 5 minutes or until soft. Stir in cayenne, cumin, and turmeric; saute for 1 minute.
Stir in stock, tomatoes, tomato paste, and sugar; return chicken to pan. Bring to boil; reduce heat and simmer 5 minutes.