Prepare the chicken and pasta water. Place your chicken breasts on a board and, using a sharp knife, slice them horizontally into two even cutlets. Season both sides generously with the salt and pepper. Fill a large pot with water, bring it to a rolling boil, and add a generous tablespoon of salt. The water should taste like the sea. This is your only chance to season the pasta from within.

Sear the chicken until golden and aromatic. Heat the olive oil in a large, heavy-based frying pan over a medium-high heat. Lay the chicken cutlets in the pan, ensuring they are not touching. You should hear a confident sizzle immediately. Cook for 4-5 minutes without moving them. The underside should turn a deep, nutty brown. Flip the chicken and cook for another 3-4 minutes. The internal temperature should reach 74°C. Remove the chicken to a plate and let it rest. The aroma of browning chicken and oil is the first promise of the meal to come.

Cook the fettuccine. Drop your fettuccine into the boiling water. Cook according to the package instructions until al dente – tender to the bite but still with a tiny white core when you bite into a strand. Reserve about 250ml of the starchy pasta water before draining. The water will look cloudy and feel slightly thick between your fingers. Do not skip this step.

Build the sauce foundation. While the pasta cooks, reduce the heat under your frying pan to low. Add the butter. It should melt gently, not brown. Once it is foaming, add the minced garlic. Stir constantly for 30 seconds until the garlic is fragrant but not coloured. The kitchen will fill with a sweet, mellow garlic aroma.

Create the creamy base. Pour in the double cream, stirring continuously with a wooden spoon. Scrape up any browned bits from the bottom of the pan; those are pure flavour. Let the cream come to a gentle simmer. You will see it begin to thicken slightly, coating the back of your spoon. This should take about 2 minutes.

Incorporate the cheese. Remove the pan from the heat. Add the grated Parmigiano-Reggiano in three additions, whisking vigorously after each until completely melted. The sauce will look glossy and smooth, with a pale ivory colour. Stir in the grated nutmeg if using. If the sauce seems too thick, add a splash of the reserved pasta water to loosen it.

Marry the pasta and sauce. Add the drained fettuccine directly to the pan of sauce. Toss everything together using tongs for about 1 minute. The pasta will absorb some of the sauce and become beautifully coated. Add a little more pasta water as needed to keep the sauce flowing and silky. You are aiming for a consistency where the sauce clings to the pasta but still pools slightly in the bottom of the bowl.

Slice the chicken and finish the dish. Slice the rested chicken breasts against the grain into thick strips. The meat should be juicy and white all the way through. Squeeze the lemon juice over the pasta and toss once more. This brightens the entire dish, cutting through the richness. Serve immediately, topped with the sliced chicken, a generous shower of fresh parsley, and extra grated Parmigiano-Reggiano.