Beurre manié
From Freepedia
Beurre manié is a dough consisting of equal parts of soft butter and flour used to thicken soups and sauces. By kneading the flour and butter together, the flour particles are coated in butter. When the beurre manié is added to a hot or warm liquid, the butter melts, releasing the flour particles without creating lumps. A liquid thickened with beurre manié should be heated for at least another 20 minutes to prevent it from tasting of flour.
