Nettle Pasta with a Sweet Potato and Mushroom Sauce

6 Portions. Wash the nettle well and place it in saucepan with just enough boiling water to cover it. Allow the nettles to cook in simmering water for a couple of minutes until the leaves are wilted and tender like spinach. Remove the nettles from the water and refresh them in cold water. Puree it in a food processor with the olive oil and Pesto until you have a smooth puree. Remove the puree from the food processor and set aside. Place all the ingredients including the pureed nettle in a food processor and process it until you have a breadcrumbs like consistency. Tip the mixture out onto a work surface and bring together with your hands so that you have a ball of dough. If it is to dry add a little water and if to wet add some more flour. Knead the mixture for a couple of minutes until it has some elasticity. Make the dough into 4 balls and cover them with cling film and place it in the refrigerator for at least 30 minutes. By Hand: Place the flour out onto a work top and make a well in the centre. In a bowl beat the egg, oil and nettle (finely chop the nettle to a puree) together, pour this mixture into the well in the centre of the flour. Using your your hands bring the flour into the egg mixture and gradually combine it until you have a dough. Knead the dough for couple of minutes until it is firm and has elasticity. Make the dough into 4 balls, cover them with cling film and place them in the refrigerator for at least 30 minutes. Remove the dough from the refrigerator and starting with one ball of dough roll it out so that it is around 1cm-1.5 cm thick. Set a pasta machine to the lowest setting and pass the pasta through it 3 times. Then set the pasta machine to a higher setting and pass it through, then reduce the setting and repeat the process to the last or second last setting so that the pasta is very thin and long. If the pasta comes sticky dust it with a little flour. Cut the sheet of pasta in half and pass each sheet through the fettuccine setting on your pasta machine. Hang the pasta up on a wooden pasta holder or weighted broom handle. Repeat this process with the remaining pasta. Bring a large pot of boiling water to the boil and place the pasta in it and cook it for around 2 minutes until al dente. Place the reserved mushroom water in a saucepan over a moderate-high heat and bring it to the boil. Place the sweet potatoes in the stock and leave them to simmer for 5-7 minutes until they are tender. Strain the sweet potato from the stock and set aside while you finish the sauce. Return the stock to the saucepan and allow it to reduce on a strong simmer until their is only a little liquid left (around 80-100ml). Melt the butter with the olive oil in a large saucepan over a moderate heat. When melted add the garlic, sage leaves, chilli (optional), wild mushrooms and button mushrooms and cook them for 5-8 minutes, stirring regularly until tender. Stir in the spring onions, basil, sweet potato and creme fraiche into the mushroom mixture until well combined. Remove the sauce from and toss the pasta in it until the sauce is well distributed throughout the pasta. Serve. Distribute the pasta among 4-6 bowls and scatter over the pine nuts and Parmesan. Serve.