Mayo Substitute by Bookseller

For anyone looking to cut some fat, I recommend this highly (and I say this as a person who has never uttered the words "this sauce is too rich"). I made it from the stuff I had lying around; YMMV:

5-6 oz. silken tofu
Half a small roasted onion
Large bunch of scallions
An enormous handful of fresh thyme, leaves only
2 tablespoons tarragon vinegar
Quite a lot of salt and freshly ground black pepper
2 tablespoons balsamic vinegar
4 tablespoons good olive oil

Whiz everything except the oil in the food processor; dribble the oil in very slowly as if you were making mayo. It will be quite runny, but will thicken to a near-mayonnaise consistency after an hour in the fridge. It's delicious right then, but gets even more delicious after a night of chilling. I wound up with about one and a third cups, which works out to roughly 20-25 calories per tablespoon -- or one-quarter of what you'd scarf if you were eating regular mayonnaise -- and about 2-3 grams of fat.