Cook the Pasta: Begin by putting a large pot of salted water on to boil for your pasta. Once boiling, add the pasta and cook according to the package instructions until al dente.

Sauté the Aromatics: While the pasta water is heating, heat the olive oil in a large, heavy-bottomed frying pan or sauté pan over a medium-high heat. Add the chopped onion and cook for 5-7 minutes, stirring occasionally, until it has softened and is starting to turn translucent.

Brown the Mince and Mushrooms: Add the beef mince to the pan with the onions. Break it up with a wooden spoon and cook until it's browned all over. Drain off any excess fat. Push the mince to one side of the pan, add the sliced mushrooms to the empty side, and cook for 5-6 minutes until they've released their liquid and are nicely browned. I find that browning the mushrooms separately in the pan like this gives them a much better flavour and texture.

Create the Flavour Base: Stir the minced garlic and smoked paprika into the mince and mushrooms and cook for one minute until fragrant. Then, stir in the plain flour and tomato purée, and cook for another minute. This step cooks out the raw flour taste and deepens the tomato flavour.

Build the Sauce: Pour in the beef stock, stirring continuously to ensure there are no lumps from the flour. Add the Worcestershire sauce and Dijon mustard. Bring the mixture to a gentle simmer, then reduce the heat to low and let it bubble away gently for 10 minutes, stirring occasionally, until the sauce has thickened slightly.

Finish with Cream and Seasoning: Turn the heat right down to its lowest setting. Take the pan off the heat for a moment to be safe. Stir in the soured cream until it's fully incorporated and the sauce is pale and velvety. Be careful not to let the sauce boil after adding the cream, as it could split. Season generously with salt and black pepper to your taste.

Combine and Serve: Drain the cooked pasta, reserving a small cup of the starchy pasta water. Add the drained pasta directly to the pan with the Stroganoff sauce. Toss everything together until the pasta is well-coated. If the sauce seems too thick, add a splash of the reserved pasta water to loosen it. Serve immediately, garnished with a generous sprinkle of fresh parsley.