In this updated traditional French dish, a confit of salmon poached in lemon-infused olive oil and garnished with salmon roe and osetra caviar is served with a cucumber salad with horseradish sauce.
In a small saucepan over medium heat, combine 2 cups olive oil and 2 tablespoons lemon zest. Heat until a deep-fry thermometer registers 120 degrees. Remove from heat, and allow flavors to infuse. Can be kept at room temperature, covered, up to 24 hours.
Make horseradish sauce: In a small bowl, mix together horseradish, sour cream, 1/4 teaspoon salt, 1/4 teaspoon sugar, and cayenne. Pass through a fine sieve into another small bowl, and transfer to the refrigerator until needed.
Combine 3 tablespoons chopped dill, remaining 1 1/2 tablespoons lemon zest, 1 1/2 teaspoons salt, the brown sugar, and pepper. Rub mixture evenly over salmon; place in a shallow bowl, and cover. Place in refrigerator, and let marinate 1 hour.
Use a mandoline or sharp knife to thinly slice cucumber lengthwise into thin ribbons. Transfer to a small bowl, and sprinkle 1 1/2 teaspoons salt evenly over cucumbers. Let sit 25 minutes. Pat dry with paper towels, and set aside.
Make the vinaigrette: In a small bowl, whisk together vinegar, remaining 2 tablespoons olive oil, 1/4 teaspoon salt, and pinch of sugar. Set aside.
Make salmon confit: Strain the reserved olive oil infusion through a fine-mesh sieve into a medium saucepan, and discard lemon zest. Clip a deep-fry thermometer to the side of the pan, and heat infused oil until it reaches a temperature of 120 degrees. Remove salmon from the refrigerator, and wipe off herbs with a paper towel. Place salmon pieces in the hot oil, and poach 25 minutes, adjusting heat if necessary to maintain a constant temperature of 120 degrees. Remove salmon with a slotted spatula, and transfer to a paper towel-lined plate to drain. Set aside.
While salmon is cooking, place cauliflower florets in a small heat-proof bowl. Bring the water to a boil in a small saucepan, and pour over florets. Let sit 1 minute, and drain in a colander. Set aside. Toss baby greens with 2 tablespoons reserved vinaigrette.
To serve, place cucumber ribbons in a mound in the center of each of four plates. Place a piece of salmon on top of the cucumbers, and top with a small dollop of salmon roe, if desired. Arrange cauliflower and baby greens on the side, and drizzle plates with horseradish sauce and remaining vinaigrette.