Mix auquafaba, vinegar, mustard, salt and maple syrup in a bowl or large glass measuring cup (preferably something deep to prevent mix from splattering) with an immersion blender until incorporated. 

Drizzle in oil slowly, 1/4 cup at a time, continuously mixing with the immersion blender. Mixture will start to become pale, thick and creamy as you keep mixing, until it reaches the consistency of mayonnaise.

Adapted from Facebook page: Vegan Meringue-Hits and Misses’ files, recipe by Hunter Noffsinger