Cook the Pasta: Bring a large pot of well-salted water to a rolling boil. Add the fettuccine and cook according to the package instructions until al dente (usually 8-10 minutes). Before draining, reserve about 250ml (a mugful) of the starchy pasta water. Drain the pasta and set it aside.

Start the Sauce Base: While the pasta is cooking, melt the butter in a large, deep frying pan or sauté pan over a medium-low heat. Add the minced garlic and cook gently for 1-2 minutes until it's fragrant and soft, but not browned. You want to infuse the butter with the garlic flavour without any bitterness.

Make the Roux: Sprinkle the plain flour over the garlic butter and stir continuously with a whisk for about one minute. This will cook out the raw flour taste and form a thick paste, known as a roux.

Add the Liquids: Gradually pour in the whole milk, a little at a time, whisking constantly to ensure a smooth, lump-free sauce. Once all the milk is incorporated, pour in the double cream and continue to whisk.

Simmer and Thicken: Bring the sauce to a gentle simmer and let it cook for 3-5 minutes, stirring occasionally, until it has thickened enough to coat the back of a spoon.

Melt the Cheese: Turn the heat down to the lowest setting. Add the 100g of finely grated Parmesan cheese to the pan. I find that stirring it in with a wooden spoon or spatula works best here to help it melt evenly without clumping. Stir until the cheese is completely melted and the sauce is smooth. Do not let the sauce boil at this stage.

Season: Season the sauce with salt and freshly ground black pepper. Taste and adjust if necessary. Remember that the Parmesan is already salty, so you may not need much extra salt.

Combine Everything: Add the drained pasta to the pan with the sauce. Use tongs to toss everything together until the pasta is thoroughly coated. If the sauce seems a little too thick, add a splash of the reserved pasta water to loosen it to your desired consistency. This starchy water is key to a silky sauce.

Finish and Serve: Stir through the chopped fresh parsley. Serve the creamy garlic parmesan pasta immediately, topped with an extra grating of Parmesan cheese and a crack of black pepper.