You will need to purchase 3 limes for 3 tablespoons of juice. To get the most juice from each lime, roll it around on the countertop a few times while applying gentle pressure, or pop it in the microwave for a few seconds.
Make the vinaigrette up to a couple of days ahead of time and refrigerate it. Shake before serving.
Use a small cookie cutter to cut the jicama into cactus shapes.