Jacques Pépin is a master of culinary technique and aptitude, as evidenced in the elegant Cognac sauce he serves on beautifully roasted chicken.

Instead of using flour, cornstarch, or roux to thicken the sauce, Pépin uses beurre manié, a special ingredient whose name means "kneaded butter" in French.

Beurre manié is a combination of butter and flour, made by vigorously kneading flour into room-temperature butter into flour to form a thick paste.

Unlike a classic roux, which is a mixture of equal parts flour and fat that are cooked together to create a thickening agent, beurre manié is not cooked before use.

Beurre manié is whisked directly into hot liquid, allowing it thicken a sauce without forming lumps. Pépin takes advantage of the way beurre manié doesn't alter flavors.

Pépin's Cognac sauce is rich in flavor on its own, and by keeping it simple with the reliable and neutral-tasting beurre manié, the sauce's nuances can really shine.