Beef Stroganoff

Pat the beef strips dry with kitchen paper. Surface water boils before it browns, and a wet strip goes grey in the pan.

Toss the beef with the flour, the fine salt and the ground peppercorns until every piece carries a thin dusty coat.

Take the soured cream out of the fridge now if you have not already. Cold cream dropped into a hot pan splits far more readily than cream at room temperature.

Heat half the butter with the oil in a wide heavy pan over high heat, until the foam has subsided and the fat shimmers.

Sear the beef in two batches, 60-90 seconds a side, until browned outside and still pink within.

Give each batch room. Tipped in all at once the strips drop the pan temperature, release their water and stew in it, and no amount of extra time afterwards will brown them.

Lift the beef and any juices onto a plate.

Turn the heat to medium, add the rest of the butter and the sliced onion.

Cook the onion for 6-8 minutes, until soft, translucent and just beginning to colour at the edges, scraping the browned residue off the base as it loosens.

Raise the heat, add the mushrooms and spread them out in as close to one layer as the pan allows.

Leave them undisturbed for 2-3 minutes, then cook for a further 5-6 minutes, until the water they release has boiled away and they are browned and squeaking against the spoon.

Stir in the Dijon mustard and cook for 30 seconds, until it smells sharp rather than raw.

Pour in the hot stock and scrape the base clean.

Simmer for 3-4 minutes, until the liquid has reduced by about a third and just coats the back of a spoon.

Take the pan off the heat entirely.

Stir two ladlefuls of the hot liquid into the soured cream in a bowl, one at a time, to bring it up to temperature gradually.

Pour the tempered cream back into the pan and set it over the lowest heat you have.

Warm it through for 2-3 minutes without letting a single bubble break the surface. Past about 80C/175F the cream separates into grains and watery whey, and whisking does not bring it back.

Return the beef and its collected juices and warm for 1 minute more.

Stir in the lemon juice, then taste and correct the salt.

Scatter with the dill and serve at once, with buttery mashed potato or plain boiled potatoes.

For something nearer the original, leave the mushrooms and the onion out and make the sauce from mustard, stock and soured cream alone. It is a sharper, plainer dish and closer to what the nineteenth-century recipes describe.