In an effort to eat less ultra processed food I have stopped buying mayonnaise and make my own.
I use the Julia Child "blender" mayonnaise recipe in a Magimix Le Micro Mini Food Processor, I highly recommend these for many uses, not just mayonnaise.
The Le Micro has a little "trough" in the top with a small hole in it, ideal for dropping in the oil. Also, the Le Micro is far easier to clean than a blender and much less left on the blade.
The recipe and method is shown from 17.40 in the video
To my taste I prefer to use lemon juice rather than wine vinegar and rather than all olive oil I use a mix of olive and sunflower oil (approx 40/60). The recipe calls for a cup of oil, I find it needs a little less (approx. 80%) and I usually add an extra tablespoon of lemon juice and 1/4 teaspoon of dried mustard powder at the end when the mayonnaise is made. It only takes a few minutes to make, keeps very well in the fridge for at least a week, and I feel tastes much better than bought mayonnaise