Add oil to a large pot and heat over medium-high heat. Season chicken with 1/4 tsp. salt and the pepper. Add to the pot and cook for 7 minutes. Remove to a plate.
Add onion and garlic and cook, stirring, 5 minutes, until lightly browned. Add the curry and cook for 1 minute. In a medium sized bowl, whisk together the condensed soup and milk, and stir into pot.
Add remaining 1/4 tsp.salt, tomato, mango, raisins, chicken and any juices from the plate. Bring to a boil, lower heat and simmer with the lid slightly ajar for 25 minutes, stirring occasionally. Serve with cooked couscous.