Pumpkin Gnocchi with Butter & Sage Sauce

The Sauce

1. Preheat the oven to 180C. Prick the potatoes and sweet potato all over using a fork.
2. Place on a large baking tray together with the wedges of pumpkin. If using butternut squash instead of pumpkin, use ½ a medium butternut squash with the seeds and fibre removed, and place skin side down.
3. Melt the knob of butter and brush the flesh of the pumpkin or butternut squash with the melted butter.
4. Put the baking tray in the oven and bake for 1 hour or until the vegetables are tender.
5. Remove from the oven and allow to cool. Cut the potatoes in half and scoop the flesh into a bowl. Scoop the flesh from the pumpkin or butternut squash and put this into the bowl also.  Either put the potatoes and pumpkin through a mouli or mash thoroughly and put into a large bowl.
6. Next, sift in the flour, add the egg yolk and mix with a wooden spoon. Season with some salt and pepper.
7. Fit a piping bag with a 2 cm nozzle and fill with some of the mixture. Have ready a floured tray and pipe lengths of gnocchi onto the tray, then cut into 2 cm lengths before poaching in a pan of boiling vegetable stock.  Alternatively, have ready a pan of boiling vegetable stock on the stove. Squeeze the mixture through the tip of the piping bag and cut into 3 cm lengths so that the pieces drop into the pan. Cook in the stock for about a minute.
8. The gnocchi are cooked when they float to the surface and you should then remove them carefully with a slotted spoon and arrange them on a tray.  You will need to cook the gnocchi in about four batches.
9. To make the butter and sage sauce, heat the oil and sauté the onion for 3 to 4 minutes until softened but not coloured. Add the sage and sauté for half a minute. Stir in the butter until melted, then remove from the heat and stir in the lemon zest. Season to taste with salt and pepper.
10. Serve the gnocchi with the melted sage butter drizzled on top.