Step 1

Place egg , mustard, vinegar, salt, in a 2-cup jar and use an immersion blender ( right in the jar). Alternatively, use a food processor,  or use a bowl and whisk by hand. Blend /whisk for 30 seconds until frothy.

Step 2

Blend well, then add a teaspoon at a time, blending between each addition-be patient here in the beginning with the first 1/4 cup of olive oil – this initial stage is the key to getting the mayo to emulsify and get creamy and thick. Once it’s creamy, then gradually add a  tablespoon at a time, blending or vigorously whisking in the remaining olive oil.

Step 3

Scrape down sides if need be, and blend until thick and creamy.

Step 4

Taste and adjust salt and acid. A little splash of lemon juice is nice here.

Step 5

Place in a 2-cup jar with a lid and refrigerate for up to 3 weeks.