Combine and mix together the fish sauce, rice vinegar, lime juice, caster sugar, red chilli, garlic, water and sesame oil in a bowl and set aside.
Cook the noodles (as per the packet instructions), before plunging into cold water and draining.
Combine and mix the spring onions, mango, red pepper, and mint in a bowl and set aside.
Preheat the oven to 200 C / Gas 6. Score the skin on the duck breasts 6 to 8 times with a sharp knife and season on both sides with salt.
Place the duck breasts skin-side-down in a non-stick pan on a low to medium heat. Cook for 6 to 8 minutes, or until the skin is golden brown and crispy, before pouring off any excess fat and flipping over the breast. Cook and seal the breast on this side for around 30 seconds before removing from the heat.
Turn the breast back onto the skin-side and place into the preheated oven for around 6 minutes for medium rare duck (see Gressingham’s website for timings on cooking duck). Remove the duck from the oven and leave to rest for 5 minutes.
Set aside two tablespoons of dressing (for garnishing later). Place the duck breasts and their juices into the remaining dressing and mix. Set aside for 5 minutes before removing the breasts from the dressing and placing them on a chopping board.
Take the drained noodles and toss them with a little oil and lightly season. Add the dressing and mango salad and mix well before dividing onto serving plates. Finely slice the duck and place on top of the salad. Drizzle the remaining dressing on top and garnish with lime wedges and coriander.