Rinse the Brussels sprouts, cutting off the base of the stem and the outer leaves, until you reach the leaves that loosen easily. Save the choicest outer leaves for a salad and toss away the rest.
Boil a pot of salted water. Cut out the hearts of the Brussels sprouts (the inner part) into quarters and blanch for about 2 minutes until they are tender, but not overcooked. If the Brussels sprouts cook too long they obtain a bitter aftertaste and smell bad.
Put the sprouts directly into a food processor and grind them into a puré with cold butter, salt pepper, honey and vinegar.