Clean the salmon. Insert the parsley stem into the gullet. Season salmon inside and out extensively with pepper and season with salt. Cut narrow julienne from vegetables, keeping fennel greens. Butter a firm large piece of aluminum foil on one side. Center the julienne, place the fish on top. Place butter flakes on top and sprinkle with lemon zest. Fold up the sides of the aluminum foil, tucking the ends (behind the head and tail) up. Above the fish, in the middle, the aluminum foil still open, pour the wine into it.
Close the aluminum foil tightly by pinching it together. Cook the fish at 200 degrees for 60 minutes.
Gently remove the fish from the stove. Open the foil, put the fish on a warmed plate, spread the julienne evenly and collect the fish broth. Transfer fish stock to a sauce pan and bring to a boil, add whipped cream and saffron. Boil a little. Add a dash of Noilly Prat, mustard and chopped fennel greens.
If you like, you can also thicken the sauce.
Tastes good with parsley potatoes.