1. In a bowl, rub the chicken thighs with a drizzle of oil and the five spice powder. Leave to marinade while preparing the sauce.
2. In a small pot combine the peanut butter, soy sauce, vinegar, brown sugar, sesame oil, chilli and water. Set over a medium heat, whisking until combined and warmed through.
3. Cook the thighs on a BBQ or grill pan until crispy and cooked through.
4. To serve, roughly chop the chicken thighs and place inside the lettuce cups. Nestle in the cucumber and carrot, then spoon over the peanut sauce and drizzle with sweet chilli. Serve immediately.