Prepare the beef: Pat the beef strips dry with kitchen paper. In a bowl, toss the beef with the flour, smoked paprika, a generous pinch of salt, and a good grind of black pepper until each strip is lightly coated. The flour will help create a beautiful, deep-brown crust and thicken the sauce later.

Sear the beef: Heat a large frying pan over a high heat. Add the butter and olive oil; the butter should sizzle and foam immediately. Working in two batches to avoid overcrowding, sear the beef strips for 60–90 seconds per side. You’re looking for a deep, mahogany-brown colour and a sizzling sound. Remove the seared beef to a plate and set aside. The pan should have lovely brown bits stuck to the bottom.

Sauté the aromatics: Reduce the heat to medium. Add the chopped onion to the pan and cook for 3–4 minutes, stirring often, until it becomes soft and translucent with a sweet, fragrant smell. Add the minced garlic and cook for a further 30 seconds until it releases its aroma.

Cook the mushrooms: Tip the sliced mushrooms into the pan. Cook for 5–7 minutes, stirring occasionally, until they have released their moisture and turned a rich, golden brown. You should hear a gentle hiss as they cook; the pan should be dry again by the end.

Build the sauce: Stir in the tomato purée and cook for 1 minute, allowing it to darken slightly. Pour in the warm beef stock, scraping the bottom of the pan with a wooden spoon to lift those browned bits (this is where the flavour lives). Add the Dijon mustard and stir to combine. Bring the sauce to a gentle simmer, then let it bubble away for 8–10 minutes until it has reduced by about a third and thickened slightly. The colour will deepen to a rich, glossy brown.

Finish the sauce: Reduce the heat to low. Return the seared beef and any juices from the plate to the pan. Stir in the soured cream until it is completely incorporated. The sauce will turn a beautiful, pale caramel colour and become velvety smooth. Taste and adjust seasoning with salt and pepper. Do not let it boil after adding the cream, or it may curdle.

Cook the noodles: While the sauce is simmering, cook the egg noodles in a large pot of salted boiling water according to the package instructions, usually 4–5 minutes, until they are just tender (al dente). Drain them in a colander and return them to the pot. Toss with a small knob of butter to keep them from sticking.

Plate and serve: Twirl a generous portion of the buttered egg noodles onto each warm plate or shallow bowl. Spoon the stroganoff over the top, making sure to get plenty of sauce and mushrooms. Finish with a final flourish of freshly chopped parsley for colour and a fresh, herby contrast.