Pour about 1.5 litres cold water into a wok or large pan that will take a bamboo steamer on top.
Add all the herbs and spices bring to the boil, and then simmer for 10 minutes.
Remove from the heat and leave to infuse for half an hour or so.
Meanwhile, set aside about 24 large basil leaves from the bunch.
Put half the remaining bunch (including stalks) into a pan with the shallots and Noilly Prat.
Boil gently until the liquid is reduced to around 2 tbsp and the shallots are soft, about 3 minutes.
Pour in the stock and boil gently until reduced by half. Add the two creams and remaining bunch of basil to the pan.
Simmer until the sauce is reduced by half and has the consistency of pouring cream, about 3-4 minutes. While it’s boiling, add a squeeze of lemon juice (if not boiling, the sauce will split).
In the meantime, shred 8 of the reserved large basil leaves and put into a heatproof bowl or small pan. When the sauce has reduced down, check the seasoning and strain the sauce through a fine sieve onto the basil shreds.
Set aside while you put the dish together.
Separate the bok choi leaves.
Trim off the stalks from the larger leaves (reserve the stalks) and arrange these leaves on the base of the steamer, like a daisy.
When you’re ready to cook the Norwegian salmon, bring the aromatic water back to the boil.
Scatter half the remaining 16 basil leaves over the bok choi.
Press the rest of the basil on top of each Norwegian salmon fillet.
Season the leaves and drizzle with some oil, then sit the fish on the leaves and drizzle with more oil and some lemon juice.
Put the bok choi stalks, smaller leaves and hearts into a large bowl.
Season with salt, drizzle with more olive oil (about 4 tbsp), 2 tbsp of the balsamic vinegar and a little more lemon juice, toss together and leave to wilt for about 3 minutes.
Sit the steamer basket in the wok or over the pan and cover, and then turn the heat to medium.
Cook for 3 minutes.
Take everything off the heat and leave to stand, still covered, for 4-5 minutes for fish that is lightly cooked inside and 6-7 minutes if you like the flesh firm.
While the Norwegian salmon is standing, heat a large non-stick frying pan until you can feel a strong heat rising – it should be 'stinking' hot. Toss in the wilted bok choi and immediately start to stir fry over a high heat for a couple of minutes until completely wilted and lightly caramelised.
Drizzle in a little more olive oil and another 2 tbsp vinegar to deglaze. Remove the pan from the heat and set aside.
Gently reheat the velouté.
Divide the stir-fried bok choi between four warmed plates.
Sit a Norwegian salmon fillet on top, pour around the basil velouté and sit some of the steamed bok choi leaves on top of each Norwegian salmon fillet to garnish.