Mousse au chocolat

Mousse au chocolat is the French dessert of melted dark chocolate lightened with beaten egg whites, sometimes with yolks and butter folded in first, set in the fridge and served cold in a glass or spooned from a bowl. In its home form it contains no cream and no gelatine: the structure comes entirely from the air in the whites and the chocolate setting as it cools, which is why a proper one is dense, dark and faintly bitter rather than fluffy and sweet. The word mousse was used for savoury and sweet foams in French kitchens from the eighteenth century, and the chocolate version appears in recipe books by the early twentieth; it became the bistro dessert of the post-war decades, served from a large bowl at the table in the style of the Paris brasserie, and it remains the dish by which the kitchen's pastry section is most easily judged because there is nowhere to hide.