Add everything but the oil to a 1-quart mason jar. Stick the immersion blender into the ingredients in the bottom of the jar and begin blending for 15-30 seconds.

Add a few drops of oil, one drop at a time, while blending for another minute.

After a minute, start pouring a slow and steady steam of oil into the jar while continuously blending, working the immersion blender up and down from the bottom of the jar. Continue this process until you have added the whole cup of oil. At this point, the mayo should be the proper consistency.

Taste test and add more lemon or salt if need be. Place a lid on the jar, label it with the date made it, and store it in the fridge for up to 7 days.

Bon Appétite!