Cook the Pasta: Bring a large pot of salted water to a rolling boil. Add the tagliatelle and cook according to the package directions until al dente. Just before draining, reserve about 250ml (1 cup) of the starchy pasta water. Drain the pasta and set it aside.

Prepare and Sear the Chicken: While the pasta cooks, pat the chicken pieces dry with a paper towel and season them generously with salt and pepper. Heat the olive oil in a large, heavy-based frying pan or skillet over a medium-high heat. Add the chicken in a single layer (work in batches if necessary to avoid overcrowding) and cook for 3-4 minutes per side, until golden brown and cooked through. Use a slotted spoon to transfer the cooked chicken to a plate.

Sauté the Aromatics: Reduce the heat to medium and add the butter to the same pan. Once melted, add the finely diced shallots and cook for 3-4 minutes, stirring occasionally, until they have softened and become translucent. Add the minced garlic and dried oregano and cook for another minute until fragrant. What works best for me is to constantly stir the garlic to ensure it doesn't catch and burn.

Deglaze the Pan: Pour in the white wine (or chicken stock) to deglaze the pan. Use a wooden spoon to scrape up any browned bits stuck to the bottom – this is where so much flavour is hiding! Let the liquid bubble and reduce by about half, which should take 1-2 minutes.

Build the Cream Sauce: Reduce the heat to low. Pour in the double cream and chicken stock, then whisk in the Dijon mustard. Let the sauce gently simmer for 3-4 minutes to thicken slightly. Be careful not to let it boil vigorously.

Combine and Finish: Stir the grated Parmesan cheese into the sauce until it has melted and the sauce is smooth and velvety. Return the cooked chicken and any accumulated juices back to the pan. Add the drained pasta to the sauce.

Emulsify and Serve: Toss everything together gently until the pasta and chicken are thoroughly coated in the creamy sauce. If the sauce seems a little too thick, add a splash of the reserved pasta water to loosen it to your desired consistency. The starch in the water helps the sauce cling to the pasta beautifully. Season with more salt and pepper if needed. Stir through the chopped fresh parsley, serve immediately with an extra grating of Parmesan on top.