How to Make It
In a fish poacher or a pot large enough to hold the salmon, combine the wine, onion, celery, peppercorns and parsley. Add 3 inches of water and bring to a boil. Add the salmon fillet (it should be fully submerged) and bring the water to a simmer. Cover and simmer gently over low heat until the salmon is just cooked through, about 8 to 9 minutes. Turn off the heat and let stand for 5 minutes.
In a medium bowl, combine all of the ingredients and mix well.
Using 2 spatulas, carefully transfer the salmon fillet to a large platter. Dab off any white bits and let stand at room temperature for 15 minutes. Cover loosely with plastic wrap and refrigerate until cool.
Garnish the salmon with the lemon and cucumber slices and serve with the raita.