Bake the potatoes: Preheat your oven to 200°C (400°F). Prick each potato several times with a fork, then place them directly on the oven rack. Bake for 50–60 minutes until the skins are crisp and the flesh feels soft when squeezed gently. You'll know they're ready when a knife slides in without resistance. Let them cool just until you can handle them, then peel off the skins while the potatoes are still warm. The steam escaping should smell deeply earthy.

Rice the potatoes: Press the peeled potatoes through a ricer or a fine-mesh sieve into a large mixing bowl. The texture should resemble fluffy snow, with no lumps remaining. Spread the riced potato on a baking tray in a thin layer and let it cool completely, about 10 minutes. This step removes excess steam, preventing a sticky dough.

Form the dough: Once cool, gather the riced potato into a mound and make a well in the centre. Pour in the beaten egg, then sprinkle the flour, salt, and pepper over the top. Using your fingertips, gently mix everything together until a shaggy dough forms. Be careful not to overwork it — stop as soon as it comes together. The dough should feel soft and slightly tacky, not wet or sticky.

Shape the gnocchi: Lightly flour your work surface. Divide the dough into four portions. Roll each portion into a long rope about 2 cm thick, dusting with flour as needed to prevent sticking. Cut each rope into 2 cm pieces. For that classic ridged look, roll each piece over the tines of a fork, pressing gently to create grooves. Place the shaped gnocchi on a floured baking tray in a single layer. You should hear a soft thud as they land on the tray; if they stick, dust with more flour.

Cook the gnocchi: Bring a large pot of generously salted water to a rolling boil. Drop the gnocchi in batches — about 15 pieces at a time — and stir gently. They will sink to the bottom at first, then float to the surface after about 2–3 minutes. When they bob up, let them cook for 30 seconds longer, then scoop them out with a slotted spoon. The cooked gnocchi should look tender and slightly translucent at the edges, and they'll feel springy when pressed.

Sear to golden perfection: While the gnocchi cook, heat a large frying pan over medium-high heat and add the olive oil. Once the oil shimmers and ripples, add the cooked gnocchi in a single layer. Let them sear undisturbed for 2–3 minutes until the bottoms turn a deep golden brown and you hear a satisfying sizzle. Flip them carefully and sear the other side for another 2 minutes. The finished gnocchi will have a crisp, caramelised crust with a soft, pillowy interior.

Finish the sauce: Reduce the heat to medium. Add the butter, minced garlic, and sage leaves to the pan with the gnocchi. Stir gently as the butter melts and foams, about 1 minute — the sage will become fragrant and slightly crispy. Pour in the chicken stock and lemon zest, then bring to a gentle simmer. Let the sauce bubble for 2–3 minutes until it thickens slightly and coats the gnocchi. The aroma should be nutty from the butter and bright from the lemon. Stir in the Parmesan until melted and smooth, then taste and adjust salt if needed.

Plate and garnish: Transfer the gnocchi to a warmed serving platter or individual bowls. Spoon any remaining sauce from the pan over the top. Finish with a sprinkle of flaky sea salt, extra grated Parmesan, and fresh parsley. Arrange a few crispy sage leaves on top for visual drama. Serve immediately while the gnocchi are still hot and the sauce is glossy.