1. Peel the potatoes and cut into small pieces. Pour 3 cups of water into the bowl. Place the potatoes in the steam basket and place the basket in the Prep&Cook bowl. Launch the P1 steam program for 20 minutes. When potatoes are cooked, place them in a separate bowl and rinse the Prep&Cook bowl in cold water.
2. Place the yogurt, dill, olive oil, mayonnaise and mustard in the bowl fitted with the ultrablade knife. Season with salt and pepper. Mix at speed 11 for 30 seconds. Cut the smoked salmon into strips.
3. Pour the sauce and celery over the potatoes and mix. Top with strips of salmon and freshly grated lemon zest. Serve warm or cold.