Cook the Pasta: Bring a large pan of salted water to the boil. Add the tagliatelle and cook according to the packet instructions until al dente. Just before draining, reserve about 100ml of the starchy pasta water, then drain the pasta and set aside.

Brown the Beef: While the pasta cooks, heat the vegetable oil in a large, heavy-based frying pan or casserole dish over a medium-high heat. Add the beef mince and cook for 5-7 minutes, breaking it up with a wooden spoon, until it's nicely browned all over. According to the Food Standards Agency, ensuring mince is cooked until steaming hot and brown throughout is key. Once browned, drain off any excess fat and set the beef aside on a plate.

Sauté the Aromatics: Add the butter to the same pan. Once it's melted, add the chopped onion and cook for 5 minutes until softened and translucent. Add the minced garlic and sliced mushrooms and cook for another 5-7 minutes, until the mushrooms have released their liquid and started to brown.

Create the Sauce Base: Sprinkle the plain flour over the mushroom and onion mixture. Stir well and cook for 1 minute to cook out the raw flour taste. This is your roux, which will thicken the sauce.

Build the Sauce: Gradually pour in the hot beef stock, whisking continuously as you go to prevent any lumps from forming. Bring the mixture to a gentle simmer. What works best for me is adding the stock a little at a time to ensure a smooth consistency.

Simmer and Season: Once simmering, stir in the Dijon mustard, smoked paprika, and Worcestershire sauce. Return the cooked beef mince to the pan. Season generously with salt and black pepper. Reduce the heat to low and let it simmer gently for 5-10 minutes for the flavours to deepen.

Finish with Soured Cream: Take the pan off the heat completely. Allow it to cool for a minute, then stir in the room-temperature soured cream until fully incorporated. Do not return the pan to the heat, as this can cause the sauce to split. If the sauce is a little too thick, stir in a splash of the reserved pasta water until it reaches your desired consistency.

Combine and Serve: Add the drained pasta to the pan with the stroganoff sauce. Toss everything together until the pasta is well-coated. Serve immediately, garnished with a generous sprinkle of fresh parsley.