Nothing tastes as good as green feels

These have a sweet and slightly nutty flavour, a pretty orange colour and a wonderfully soft texture.

1. Preheat the oven to 220 C (425 F/Gas 7).
2. Cut the sweet potato in half and place on a baking sheet, cut side down.
3. Roast on the centre shelf for about 30 minutes, or until tender.
4. While the sweet potato cooks, make the pesto. Toast the hazelnuts in a dry frying pan over a medium-low heat until golden and the skins have split.
5. Rub between a rough tea towel to help get the peel off.
6. Place in a food processor together with the rest of the ingredients.
7. Run at high speed until the desired consistency is reached, adding a splash of water if needed.
8. When the sweet potato is cooked, leave until it is cool enough to handle then scoop out the flesh and mash it with a fork in a wide bowl.
9. Stir in the egg, salt and nutmeg and mix until combined.
10. Sift together the flours and add two-thirds to the sweet potato.
11. Stir together quickly until combined.
12. Dust a work surface with some of the remaining flour and turn the dough onto it. Knead the dough very gently with your hands, adding more flour if needed.
13. The dough should be moist but not sticky. Divide the dough into four portions.
14. Dust with more flour and roll one portion into a long log, 1 cm wide.
15. Use a knife or metal pastry scraper to cut the log into 2.5 cm pillows.
16. To shape the gnocchi, dust a fork with flour, place a piece of gnocchi with the cut side towards the back of the fork, press lightly with the fork and roll it down to create the tiny ridges.
17. Alternatively, simply press the fork into each gnocchi – they will be more square, but will still taste good.
18. Repeat with the remaining portions.
19. Bring a large saucepan of salted water to the boil over a medium – high heat.
20. Carefully drop in about 15 gnocchi. When they float up to the surface (after about a minute), wait 30 seconds and then fish them out of the water with a slotted spoon.
21. Keep warm while cooking the remaining batches of gnocchi.
22. Serve them warm with a few spoonfuls of Kale & Hazelnut Pesto (or whatever you prefer) and a drizzle of olive oil.
23. You can also save the gnocchi for later and give them a quick fry in a buttered skillet together with vegetables or any kind of sauce.

Extract taken from Green Kitchen Stories by David Frenkiel and Luise Vindahl.
Photography by David Frenkiel.