Egg Sauce

Two versions of the same thing: chopped hard-boiled egg suspended in a warm white sauce, traditionally served with poached fish or boiled poultry. The only real trap is the phrase "melted butter".

• "Melted butter" is a sauce, not butterIn Victorian British cookery melted butter means a thickened butter sauce — roughly a tablespoon of flour cooked in an ounce or two of butter, let down with about half a pint of water or fish stock and simmered until smooth. Plain liquid butter will split the moment the egg goes in and will not "boil up" as directed.
• Egg timingA full quarter of an hour gives grey-green yolks and a rubbery white. Ten minutes at a bare simmer for a large egg, then straight into cold water, gives firm yolks that still dice cleanly.
• Why the second version discards whiteWhy the second version uses only part of the white -- The recipe chops only two-thirds of the whites and gives no reason; a smaller proportion of white keeps the texture from going rubbery, and the yolk carries most of the body. It is worth following.
• Cold eggs cut betterThe instruction to wait until the eggs are "quite cold" is practical, not fussy. Warm yolk crumbles and clouds the sauce instead of holding as dice.
• Don't boil the second versionThe first recipe boils the egg into the butter sauce; the second builds it in the sauceboat and pours hot sauce over. In that case get the white sauce properly hot before it meets the eggs, since the boat will not go back on the heat.
• QuantityThe recipe calls for three or four eggs; it gives no quantity of sauce. Season the finished sauce as well as the eggs.
• ServingStandard partners are poached or boiled white fish, salt cod, and boiled fowl. Keep it warm over hot water rather than direct heat.