This can be made using an immersion stick blender, food processor, blender, or by hand using a whisk.
In a small bowl or mason jar, add the egg, salt, dry mustard, lemon juice, and white wine vinegar. Place the immersion blender in the ingredients and mix 20 seconds until the ingredients are combined.
The next part is the emulsion of oil. With the blender running on high speed, begin slowly adding the oil in small amounts continuing to use the blender to incorporate. Add a little at a time until ¼ of the oil has been emulsified. Then you can add the remaining oil in a thin steady stream. The mayo should be turning white, creamy, and thick as you are adding and blending the salad dressing. Continue doing this until all the oil has been added.
That’s it. Just a few minutes and you have a delicious homemade mayonnaise.
If you want to make a larger batch of this mayonnaise. It is best to make several small batches rather than one large one. There will be less chance of the mayo breaking on you.