When cooking meat in large chunks (ie steaks, beef or fish, whole chicken breasts, etc) once done cooking, let the meat sit for 5 minutes as it continues to cook. Don't cut it cuz it'll let all the juice out & become DRY!! After the 5 minutes, cut it & if not done then cook it a little more. Cutting meat too soon after cooking will let all the juices out & dry it out big time.
Otherwise cut the chicken into strips, it cooks faster & isn't as dry.