With a sharp knife or scissors, remove the leaves from the fennel. Place it, along with the salt, peppercorns and bay leaves, in a saucepan with about 600ml/1 pint of water. Set aside the fennel bulb to use later.
Bring to the boil and then remove from the heat.
Carefully add the salmon to the pan. Cover and leave for 15 minutes, then remove the salmon and allow to cool.
To make the dressing, place the plum tomatoes, anchovy fillets, chopped onion, lime juice, groundnut oil, basil leaves, red chilli, fish sauce and roasted peanuts in a blender, then pulse to a slightly chunky paste.
Add the fennel bulb to a saucepan of boiling water, cook for a few minutes until softened, then finely slice it and place in a large bowl.
Break the salmon into large chunks, then toss with the fennel. Add the beans and sugar snaps, and salt and freshly ground black pepper to taste.
Pour over the dressing and arrange on a serving plate. Serve straightaway.