Place the salmon in a large fish poacher, cover with boiling water, add the wine, bay, peppercorns, onion, lemon, parsley and celery.
Place over medium heat and simmer for 10 minutes for every inch of maximum filet thickness.
When ready, reserve fish to a platter and serve with the sauce.

While salmon is cooking…
Place the egg yolks, water, lemon, cayenne, tarragon and mustard in a small saucepan over low heat and whisk until thickened, moving the pan on and off the heat to regulate the temperature.
When hot and thickened, whisk in the butter in several batches to emulsify.
Serve with the salmon