Heat the oven to 160 C / 320 F. Butter 4 ramekins (150 ml each) generously, then dust the insides with finely grated Parmesan, tipping out any excess.

Place the ramekins in a deep baking or roasting pan large enough to hold them without touching. Set aside.

Bring a kettle of water to a boil for the water bath.

Pour the cream into a small saucepan and set over medium-low heat. Warm until just steaming, around 80 C / 175 F. Do not let it boil.

Remove from heat and stir in the grated Parmigiano-Reggiano until fully melted and the mixture is smooth.

In a bowl, whisk the 3 whole eggs and 2 egg yolks together until combined.

Pour the warm Parmesan cream slowly into the eggs while whisking constantly. This is the temper step - pouring too fast will scramble the eggs.

Add the nutmeg, white pepper, and a small pinch of salt. Taste the mixture - it should be well-seasoned. Remember it will taste slightly less salty once set.

Strain the custard through a fine-mesh sieve into a jug. This removes any cooked egg threads and gives a smoother texture.

Pour the custard evenly into the prepared ramekins, filling each about three-quarters full.

Pull out the oven rack slightly, place the baking pan on it, and pour the boiling water into the pan until it reaches halfway up the sides of the ramekins. Slide the rack back in carefully.

Bake for 30 to 35 minutes, until the custard is just set at the edges but has a slight jiggle in the center when gently shaken. The surface should be pale and barely colored.

Remove the ramekins from the water bath and rest on a wire rack for 5 minutes before serving or unmolding.

Melt 30 g butter in a small skillet over medium heat. Once it foams and turns golden and nutty-smelling, add the sage leaves and fry for 30 seconds until crisp.

Drizzle over the unmolded or in-ramekin flan just before serving.

To unmold, run a thin knife around the inside edge of each ramekin, place a warm plate face-down on top, and invert firmly in one motion. The flan should release cleanly.

Serve immediately with brown butter and sage, mushroom cream sauce, or a simple tomato passata.