I've missed having access to yummy vegan mayo, such as Vegenaise and Hellman's, since moving from the UK to Italy last year. The local supermarkets have their own brands, but they come in teeny tiny little jars which were not quite cutting it for me. I decided to research DIY recipes and am blown away at how simple it is! Only a few ingredients blitzed together using an immersion blender, and voila! A full-sized mayo jar that keeps for several weeks. The key here is starting with everything at room temperature and using soy milk. Soy milk emulsifies with the oil and gives that smooth and creamy texture. I do not recommend using olive oil. In my experience, it's too strongly flavored and results in bitter mayonnaise. Not terrible, but not great either.