Excluding the oil, blend all of the ingredients in a food processor/blender.
While blending, very slowly drizzle the oil into the feed tube, allowing time for the egg to absorb the oil and emulsify.
If you feel nervous, occasionally turn off the blender and check to see if it's emulsifying.
Store in the refrigerator. Your mayonnaise should last for about 1-2 months before the oil may begin to separate.
