For curry paste, mix paste ingredients in a small bowl. Combine half of curry paste with chicken cubes; set aside. Heat olive oil in a wok over high heat. Add onions and garlic and stir-fry for about 1 minute. Add coconut milk and remaining green curry paste. Cook, stirring, for about 5 minutes. Add soy or fish sauce and bring to a boil. Add chicken, bell peppers, carrots, half and half and arrowroot starch mixture. Bring to another boil, then, reduce heat to low and simmer until sauce thickens, about 15 minutes. Add mango and heat through.