The word—or phrase actually—translates literally as “short boil,” making reference, I suppose, to the short time it takes to cook fish. At any rate, when you steam or poach fish in a court-bouillon the fish itself takes on the flavor of that in which it was poached. So in the case of this today, the fish took on a light wine/garlic/onion flavor (the liquid is then either discarded or used as a base for a soup; it can be frozen for future use).
And when the fish is done it is delicious as is, either warm or chilled. To turn this beautifully flavored fish into a salad one needs only to flake it and mix it with whatever ingredients you prefer. The one pictured, I mixed it with red onion, parsley, red pepper, and mayonnaise. If you have an aversion to mayonnaise the salad can also be made with a light vinaigrette (and possibly capers). Poached potatoes can be diced and added with a bit of mustard and dill, or even diced and seeded cucumber after the fish has cooled. So you should get the picture…this is really about the cooked fish rather than the recipe itself. Once the fish is poached or steamed it will be flavorful enough that whatever you mix with with will only be an enhancement. The sky is the limit.