Épinards au Gratin

Épinards au Gratin (spinach under a browned cheese crust) teaches what gratiner means: the oven forms the crust, it does not cook the dish beneath it. Know the one true thing before touching a pan: the spinach must enter the gratin hot, concentrated, and free of loose water. If it is wet, the butter and cheese slide into a puddle; if the oven must dry it, the leaves tire before the top colors.

The short formula assumed a vegetable station had already blanched, pressed, and chopped spinach in quantity, plus a fierce service oven with a salamander, the overhead grill, waiting if the crust lagged. This is not a dish that needs a saucier on staff or a stock never off the fire. At home, a wide skillet, a shallow broiler-safe dish, and a fully heated 475°F oven do the work. This version scales the entry to 1½ pounds of spinach while preserving its defining proportion: three ounces of butter and two and one-half ounces of grated cheese for every pound. Brigade batch handling is scaffolding and can go; drying the spinach in butter, working in the cheese, and forming a rapid gratin are the dish, so they stay.

The finished spinach should be deep green and supple beneath a mottled golden crust, with butter shining at the bubbling rim. Your decisive step is the pan-drying: keep working until a spoon drawn through the spinach reveals no loose water underneath.