Place chicken in a skillet and season with salt and pepper. Pour in coconut milk and bring to a boil over high heat. (Add water, if necessary, to cover chicken.) Reduce heat to medium-low and simmer, uncovered, until chicken is opaque and firm, 15 minutes. Transfer chicken to a plate and let cool. Discard coconut milk. When cool enough to handle, shred chicken into small pieces using your fingers.
Blend mayonnaise with sour cream in a medium bowl. Stir in lime juice, relish and celery. Add chicken, pineapple, oranges and peanuts. Season with salt and pepper. Gently fold to blend and coat ingredients. Refrigerate until ready to serve. Sprinkle with coconut just before serving.