Step 1

Using the tall, narrow mixing cup that came with your immersion blender (or a tall, narrow cup or jar the same diameter) to blend the mayonnaise. Place the egg yolks, Dijon mustard and vinegar in the jar with 1 1/2 teaspoons water, and stir with a spoon to combine well.

Step 2

Carefully pour the canola oil on top of the egg yolk mixture, so it rests on top without disturbing the egg yolk mixture. With the power off, carefully submerge the mixing element of the immersion blender straight down into the jar, so it’s flush against the bottom. Now turn on the power, and slowly pull up up the blender; the ingredients will emulsify as you pull up. Remove and power off the blender, and scrape mayo on the blade into the jar.

Step 3

Use a flexible spatula to transfer the mayo into a small or medium mixing bowl. If there are any droplets of oil visible, give the mayo a good whisk. Slowly dribble in the olive oil, whisking constantly while you do so, until all the olive oil is incorporated. (NOTE: Ask someone to hold the bowl while you whisk, or place a kitchen towel or two inside a large, heavy pot, and place the mixing bowl in the towel-lined bowl. That’ll hold it steady and make it easier for you to whisk.) Whisk in the salt. Will keep for two weeks refrigerated in a closed container.