When creating emulsified dressings, keep in mind that it is important to carefully follow this procedure, and to have all the ingredients ready and pre-measured prior to starting (Mise en Place). It is important to slowly drizzle in the oil, and then to turn off the processor as soon as you have completed adding the oil. The drizzling of oil must be slow enough for the ingredients to incorporate, but not so slow that the dressing breaks down. Although not listed, this dressing will work well if one avocado is added to the first three ingredients. Also, if you are sensitive to onions, or find them particularly strong, reduce the quantity to half an onion. If the dressing seems too thick, then thin it down with a small amount of water.