Montpellier Butter (Green Butter)

Beurre Montpellier (Montpellier green butter) teaches the rule behind every cold emulsion: control the water before you add the fat. It should glow a deep herb green, taste first of butter and fresh leaves, then answer with caper, gherkin, anchovy, and cayenne. The one true thing to know before touching a pan is this: the blanched greens must be pressed until they cannot surrender another drop.

The original formula assumed a garde-manger, the cold-kitchen cook, with a mortar, a tammy cloth, and enough hands to work one and one-half pounds of butter for a grand cold-fish service. Here the quantity is quartered for eight appetizer portions, while a small food processor replaces the mortar and a fine-mesh sieve replaces the tammy. The fractions of yolk are weighed so the original proportions survive. The long pounding and brigade volume were scaffolding; the two-minute blanch, forceful pressing, ingredient sequence, gradual oil, and final sieving are the dish itself.

Once made, the butter is generous and wonderfully practical: spread it over toast, spoon it beside chilled salmon, or let it soften across slices of cold trout. One cook, one stove, one evening. Press those greens absolutely dry, and the rest will follow.