Preheat the oven to 190°C/375°F/Gas mark 5, and line a baking tray with baking parchment. Put the squash in the tray and season with salt, pepper and 2 tablespoons of olive oil. Bake for about 35 minutes, until golden and soft . Remove from oven and leave to cool completely.
Place the squash in a blender along with the spices and beaten egg then blitz to form a paste.
Using 2 teaspoons, shape the paste into a quenelle, lightly dredge the quenelle with flour, then place it on a plate. Repeat with the remaining mixture (at this point, the gnocchi can be frozen then cooked when needed)
Bring a large pan of salted water to a gentle boil. Cook the gnocchi in batches for 1–2 minutes, or until they float to the surface of the water. Drain.
Place a large frying pan over medium–high heat with the remaining olive oil. Add the garlic and sage, cook for 1 minute, then stir in the gnocchi. Season to taste and add the lemon zest and juice. Divide everything between 2 plates and serve immediately.