Piston is the southern French version of Genoa’s pesto. Pesto is made with basil and garlic but also contains pine nuts, sometimes walnuts, and usually Parmigiano Reggiano. Pistou, a mixture often dolloped into vegetable soup, usually contains neither cheese nor nuts but frequently contains tomatoes. Purists insist that pistou (and pesto) be made by hand in a large mortar, but most of us don’t have a mortar, much less one large enough to do the job efficiently. So I give in and use a blender. The herb crust has an assertive flavor of its own that matches that of the pistou. I don’t combine the tomatoes with the pureed basil because they turn the basil a rather dull green—I add them to the dish separately. The egg yolk is optional. It turns the basil mixture into a very light mayonnaise and helps hold it together, but if you don’t mind seeing little oil droplets in the basil mixture or you’re worried about raw egg yolks, just leave it out. In this recipe the basil leaves are quickly blanched, which keeps the pistou a bright green and softens its flavor somewhat. Pistou made with unblanched leaves will taste fine but takes on a murky gray color.
Season the salmon liberally on both sides with salt and pepper and let sit in the refrigerator for between 30 minutes and 4 hours. You can also soak the salmon for 2 hours in brine and add the pepper just before sautéing. Pat dry, season with pepper only if you’ve used brine, and sprinkle the top and bottom with the chopped herbs. Press the herbs onto the salmon to help them adhere. Keep in the refrigerator until you’re ready to sauté.
Make the pistou within an hour of cooking the salmon—if made sooner it will lose color. Bring
Just before sautéing the salmon, gently heat the pistou mixture in a saucepan while stirring. Don’t allow the pistou mixture to come to a boil, especially if you’ve used an egg yolk, which will scramble.
Sauté the salmon fillets, pat them with a paper towel to eliminate fat—be careful not to rub off the herbs—and transfer them to heated plates. Wipe out the hot sauté pan, and add in the chopped tomatoes, stirring them just long enough to warm them. Ladle the pistou over and around each piece of salmon and spoon the warmed tomatoes over just before serving.
© 2001 James Peterson. All rights reserved.