1. Clean and chop the leeks. Pour 3 cups of water into the bowl. Place leeks in the steam basket and place the basket in the Prep&Cook bowl. Launch the P1 steam program for 25 minutes.
2. At the end of the program, let leeks cool. Empty the water from the bowl and attach the ultrablade knife.
3. Peel the shallot. Place in the bowl with mustard, oil, vinegars, salt and pepper. Mix at speed 11 for 50 seconds. Serve leeks along with the vinaigrette.