Marinate the chicken. Slice each chicken breast into 5 strips and marinate for about 30 minutes. Whilst the chicken is marinating you can make the sauce. Put the peanut butter, coconut milk, water, sweet chilli sauce and soy sauce in a small pan. Warm gently, stirring constantly, until everything has melted. Simmer for 1 to 2 minutes until the sauce thickens. Remove from the heat, then stir in 1 tsp of the leftover lime juice and set aside.