Step 1

Put the carrot, cucumber and red onion in a mixing bowl. Add the lime juice, sweet chilli sauce, fish sauce and a good pinch of salt and grind of black pepper. Toss well to coat the vegetables, then chill for 15 minutes, tossing halfway through.

Step 2

Meanwhile, cut the baguette almost all the way through, then 
pull out and discard (or keep for breadcrumbs) most of the spongy layer of bread inside. Spread one side of the baguette with the mayonnaise and the other side 
with char siu/hoisin sauce.

Step 3

Squeeze the marinade from the veg (discard the marinade) and pile the veg into the baguette. Thinly slice the meat (leave prawns whole if using those), then arrange on top and sprinkle over the coriander. Wrap and chill until ready to eat.