Preheat oven to 350 degrees F. Cut chicken into bite-size chunks. Squeeze juice from 1 lime (about 2 tablespoons juice); cut remaining lime into wedges.
In a large saucepan combine coconut milk, the lime juice, soy sauce, and crushed red pepper. Add chicken and bring to boiling; reduce heat and cook, covered, for 12 to 15 minutes or until chicken is cooked through, stirring occasionally.
Meanwhile, spread flaked coconut in a shallow pan. Bake, uncovered, for 4 to 5 minutes or until golden, stirring once.
Transfer chicken and cooking liquid to a bowl. Add mangoes; toss to coat. Sprinkle with toasted coconut. Spoon onto lettuce leaves to serve. Pass lime wedges.