Heat a griddle pan (or BBQ) over a high heat. Combine the prawns with the char siu sauce and place onto the griddle pan. Cook for around 2 minutes per side, until pink and slightly charred. Set aside.

Mix the rice and sugar snap peas with the mango, sesame oil, soy sauce and mirin. Separate the leaves of the gem lettuce and spoon a little rice mixture into each one. Top with the prawns. Sprinkle over the crushed peanuts and a little Chiu Chow Chilli Oil if desired.