You can make the gnocchi days or weeks ahead and freeze it, then just bung it into boiling water on the day and toss with the creamy pesto sauce.
1kg large floury potatoes
2 egg yolks, beaten
1 tsp salt
pinch ground nutmeg
180g plain flour, plus extra for handling
4 tbsp pesto
1 litre salted water or vegetable stock for cooking
4 tbsp cream
sea salt and pepper
basil leaves for serving
Heat the oven to 180C. Prick the potatoes well and bake in their jackets for 1 hour until tender. Remove, cut in half and allow to cool just enough to handle.
Mash the potato or put through a potato ricer. You should have about 800g mash. Beat in the egg yolks, salt, nutmeg and flour until smooth and slightly sticky.
Divide the mixture into six. On a floured bench, roll out each piece into a long sausage – the trick is to do this lightly and evenly, gently easing it longer and longer. Cut into 2cm sections. With the tip of your forefinger, roll each piece onto the inside tines of a fork, then let it drop onto a lightly floured tray. (You can freeze the gnocchi on the tray, then transfer to a sealed bag when frozen.) To cook, drop the gnocchi in batches into a large pot of boiling salted water, let them rise to the surface, then cook for a further 60 seconds.
Remove with a slotted spoon to a large bowl and keep warm while cooking the rest. In a bowl, gently mix the pesto with cream, sea salt, pepper and 2 tbsp of the cooking water. Add the gnocchi and toss well, then divide between warmed pasta plates. Scatter with basil and serve.