Œuf en Gelée

The egg in aspic is a survivor of the old charcuterie and traiteur trade. Set jellies of clarified stock — aspic — were a staple of classical French cold cookery, and the egg version coalesced into its familiar form in the early twentieth century, the soft egg with white ham settling as a cold hors-d'œuvre rather than a garnish. By the 1930s it was a standard offering of charcutiers and bistros, served in the small oval mould that became its signature shape, with the now-fixed garnish of poached egg, jelly, white ham and tarragon. It sits in the same repertoire of bourgeois and bistro cold egg dishes as œufs mayonnaise, distinguished by being suspended in trembling aspic.

The first impression is the contrast of temperatures and textures: the aspic is cold, clear and quivering, breaking cleanly under the fork with a savoury, lightly winey richness from the stock and Madeira. The ham reads salty and firm, the tarragon a thread of aniseed perfume through the jelly. Then the egg — the yolk poached just to runny, spilling soft and warm-tasting into the cool jelly around it, white tender, faintly yielding. Well made it is limpid and glossy, the egg centred and the yolk liquid. A jelly set too hard turns rubbery; a yolk overcooked to firm loses the whole point of the dish.

The dish turns on gelatin's sol-gel transition and on poaching control. Gelatin — collagen thermally denatured into a soluble protein — dissolves in the warm stock and, on chilling, its chains partly re-coil into a junction-zone network that traps the liquid as a thermoreversible gel; because that gel melts near 35°C, just below body temperature, the aspic stays firm and trembling when cold yet softens the instant it reaches the mouth. The stock is clarified first — classically with a raft of egg white and lean meat that, as it coagulates, snares the fine cloudy particles — so the set jelly is glass-clear. The egg is poached only briefly, the white coagulating around 62 to 65°C while the fattier yolk stays liquid below about 70°C, then cooled, so that under the set aspic the yolk remains runny. The mould is layered and chilled in stages so the garnish stays suspended where it is placed.