1. Prepare the vinaigrette: Whisk together the lemon juice, mustard, and honey in a bowl. Add the olive oil and whisk until the dressing thickens. Add the salt and pepper, taste, and add more if desired. Set aside.
2. Prepare the salad: Remove any large stems from the watercress. (Small stems are fine.) Chop delicately by making a few random slices through the whole bunch. In a bowl, combine the watercress with the curly endive (or lettuce), cucumber, and red onion. Cover, and refrigerate until ready to serve.
3. When ready to serve, preheat the oven to 375 degrees F. Heat a heavy, ovenproof skillet, such as cast iron, over medium-high heat. Season the flesh side of the salmon with salt and pepper. Add canola oil to the pan and place the fish flesh side down in the skillet. Cook undisturbed, until lightly browned, 3 to 5 minutes. Carefully slip a spatula under the fish and turn over (tongs also work well).
4. Transfer the skillet to the oven to finish cooking, approximately 4 to 6 minutes, or until the fish is almost opaque throughout but still moist.
5. Divide the salad onto individual plates. Place the salmon (leaving the skin in the skillet) into the center of each plate, on top of the salad. Whisk the vinaigrette and spoon generously over the fish and greens.
Source: Hannaford fresh Magazine, September - October 2006