Sauce Béarnaise — Tarragon and Shallot Butter Emulsion

Béarnaise is the steak-lover's hollandaise — a warm butter emulsion built on a tarragon-and-shallot-infused vinegar reduction rather than plain lemon, giving it an aromatic complexity that makes it the undisputed partner for grilled beef. The reduction is the soul of the sauce: shallots in fine brunoise, cracked white peppercorns, and a generous handful of tarragon stems (save the leaves) are simmered in white wine vinegar and dry white wine until reduced to two tablespoons of fragrant, thick liquid. This is strained, cooled slightly, and whisked with egg yolks over a bain-marie at 55-62°C. The technique from this point mirrors hollandaise exactly: clarified butter in a thin stream, whisking constantly, until the sauce reaches a thick, spoonable consistency. The reserved tarragon leaves, cut to a fine chiffonade, are folded in at the end with a pinch of chervil. The finished béarnaise should hold its shape on a spoon, taste of tarragon and vinegar with rich butter in the background, and carry a gentle warmth from the white pepper. The reduction must be strong enough to assert itself through the butter — if the sauce tastes primarily of butter, the reduction was too dilute. Béarnaise tolerates no reheating — it is made à la minute and served immediately. The bain-marie temperature is critical: below 55°C the yolks will not thicken; above 65°C they scramble into an irreversible curdle.