You can buy food processors that are small, usually marketed for preparing baby food! They would be good for anyone making one-size portions a lot of the time. Or some standard size food processors come with a small bowl as an extra, it is intended for chopping herbs and other things in small quantities. I have the same problem and it is one of the reasons I don't puree things as much as I ought to, so I'm thinking about buying one of the small ones.