In a food processor, start whizzing up the garlic, lemon juice and mustard so it's smooth.
Add the aquafaba and whizz again to blend.
Add the olive oil, and keep whizzing.
Add the salt and taste. Add more lemon juice or salt as needed.
It's not an exact science, and you'll know when you reach the right 'flavour' and consistency.
Keep the mayo in a jar in the fridge. It keeps for at least a month.
Omit the garlic and olive oil for a less 'Spanish' and more 'French' tasting mayonaise.
Eat on everything. Fries, sandwiches, burgers.. add to coleslaw. I wouldn't add it to smoothies though. That would be weird.