With the machine running, drizzle the olive oil in a slow, steady stream. Slow is the name of the game here. You want this to be painfully slow for the first 30 seconds or so, just until you see some emulsion happening. After that happens, you speed up your stream, but just slightly. Keep pouring the oil until the mixture emulsifies and thickens like, well, mayonnaise. If the aioli is looking very thick and you have more oil left, quicken your pour and get it all in there. The whole process of streaming olive oil will take between 60 and 90 seconds. Taste for acid and seasoning, I found I wanted more lemon juice and salt each time I made it. If you add more salt and/or lemon juice, just pulse the processor quickly to incorporate it.