Once you have experienced home-made mayonnaise you will never be able to go back to the processed shop version. Mayonnaise is made from raw eggs and therefore should be made in small batches, stored in the fridge and used within 2 days.
1 large egg yolk, at room temperature
1/2 teaspoon mustard powder
1 cup olive oil
1 teaspoon white-wine vinegar or cider vinegar
2 teaspoons fresh lemon juice
1/4 teaspoon salt
Whisk or blend in your NutriBullet, the egg yolk, mustard, and 1/4 teaspoon salt until combined well.
Now add the olive oil drop by drop until the mixture begins to look like mayonnaise.
Add the vinegar and lemon juice, until well blended.
It is important to add the oil very slowly until it is completely emulsified.