Russian Sauce

A velouté-style sauce sharpened with mustard, horseradish and lemon, finished with cream. It comes together in under ten minutes, and the only real risk is splitting it at the end.

• Add the lemon juice off the heatAcid plus cream plus a hot pan is how this sauce breaks. Stir the cream in first, take the pan off the burner, then add the lemon juice, and reheat gently without letting it boil.
• White Stock IIIA cross-reference to another entry in the same book; white stocks in books of this kind are generally light veal or fowl stocks, lightly seasoned if at all. A good low-sodium chicken stock stands in directly; taste before adding the quarter teaspoon of salt, since commercial stock is usually already salted.
• "Made mustard"Prepared mustard from the jar, as opposed to dry mustard powder. A plain smooth paste suits the sauce better than a sweetened or grainy one.
• HorseradishFreshly grated root, whose pungency fades on standing and is much reduced by cooking. Bottled horseradish, drained of its vinegar, is the practical substitute; if the finished sauce tastes flat, stir a little more in at the end rather than during the two-minute cook.
• The roux is deliberately heavyThe roux is fat-rich -- Three tablespoons butter to two of flour is more butter than the usual equal-weight roux. Cook it briefly before the stock goes in so the sauce does not taste of raw flour, but do not let it colour.
• StrainingThe instruction to strain removes the chives and horseradish shreds, leaving only their flavour. Skip it if you want a rustic sauce with visible green, but expect a coarser texture.
• YieldAbout a cup and a quarter, enough for four to six portions of steak. It thickens as it stands; loosen with a spoonful of stock when reheating.