Heat oil in 8-quart pot over medium-high heat. Season chicken with salt and pepper. Add to pot; sauté for 5 minutes or until lightly brown. Remove chicken from pot.
Add onion and garlic to pot; cook for 3 minutes or until softened. Add curry and cayenne; cook 1 minute.
Whisk milk into soup in small bowl. Add to onion mixture. Add chicken, tomato, mango and raisins. Partially cover; simmer 30 minutes.
Serve with white rice if desired.