¼cupplain Greek yogurt (or another 1/4 cup mayonnaise)
2tablespoonsheavy cream
Kosher salt and freshly ground black pepper(to taste)
Pinch cayenne pepper
Instructions
Put the salmon in a large pot (you can cut salmon in two pieces for a big round pot), cover with cold water, add 2 teaspoons of salt, and bring to a boil. Turn off the heat, and leave the salmon in the covered pot for 10 minutes.
Remove the fish from the liquid and refrigerate until chilled (unless you want to serve it warm or at room temperature, in which case cool it until it is the temperature you want). If there was skin on the fillets, peel it off.
Meanwhile, in a food processor or blender, combine the cilantro leaves, shallots, and Dijon. Puree, add the mayonnaise and yogurt, if using, cream, salt, pepper, and cayenne and puree. Taste and adjust seasonings.
Serve the chilled fish with the sauce on the side.
Notes
The great news is that this can be made up to a day in advance, both the sauce and the fish. In fact, the salmon has to be made several hours in advance if you do want to serve it chilled, though room temperature or warm poached salmon is also lovely.