To make the supremes:Stand your citrus up on your cutting board, and run your knife in-between the rind and the flesh. Using a knife, remove the peel and all of the white pith from the sides.
Next, carefully run your knife in-between the flesh and membrane of each segment, using a controlled slicing motion to cut towards the center of the citrus. When done correctly, your segments should be 100% citrus flesh without any seeds, pith or membrane.
Sort through the watercress--keeping any small stems, and removing the leaves from the tougher stems. Trim the base of the raddichio and tear the tears into small strands. Remove the outer, tougher leaves of the escarole and base, and tear into large pieces. Tear butter lettuce into bite size pieces. Wash and dry the leaves in a salad spinner thoroughly.
Prepare Dressing:Place all of the ingredients except the oil in a medium, nonreactive bowl and whisk to combine. While whisking continuously, add the oil in a slow, steady stream until it’s fully incorporated. Refrigerate in a container with a tightfitting lid for up to 4 days.