For the pasta, soak the saffron in 2 teaspoons of warm water.
Sift the flour into a bowl and add a large pinch of salt. Make a well in the centre and crack in the egg. Mix the flour into the egg, gradually adding the egg yolk and saffron liquid to form a smooth elastic dough. Turn the dough out onto a floured work surface and knead for about ten minutes. Wrap the dough in cling film and chill in the fridge until needed.
Technique: Kneading bread Preheat the oven to 220C/430F/gas 7.
For the squash, slice the squash and arrange on a baking sheet. Season with salt, freshly ground black pepper and the chilli flakes. Drizzle over the oil and roast for 20-25 minutes, or until tender and golden-brown. Chop into bite-sized pieces.
For the mushrooms, melt the butter in a pan and fry the garlic and mushrooms for 4-5 minutes, or until the mushrooms are tender. Stir in the parsley, season with salt and freshly ground black pepper and add the wine. Cook for about 1-2 minutes, then stir in the cream and set aside.
For the sage butter, melt the butter in a heavy-based pan. Cook gently over a low heat until the butter turns a light nut-brown, taking care not to let it burn. Remove from the heat and set aside.
For the pasta, remove the dough from the fridge and knead for 5 minutes to soften it. Starting at the lowest (thickest) setting, feed the dough through the machine, turning the handle with one hand and holding the dough as it comes through the machine with the other. Change the setting on the pasta machine to the next-thickest setting and feed the pasta sheet through the machine again, as before.
Technique: Rolling pasta using a pasta machine Repeat this process 3-4 more times, changing the setting down each time. At one point, you'll need to cut the pasta sheet in half lengthwise or it will become too long to handle. The pasta should be quite thin, but still easy to handle without tearing. Don't be tempted to skip settings or the dough may tear.
Once the pasta sheets have reached the thinnest setting, trim the edges.
Bring a large,wide pan of salted water to the boil. Cook the pasta sheets, in batches, in the water for 3-4 minutes, or until al dente. Drain, then cut out rounds using a 8cm/3in cutter. Brush the pasta rounds with a little olive oil.
To serve, tear up the sage leaves, reserving a few for garnish, and add to the nut-brown butter. Gently reheat. Place one pasta round on each serving plate and spoon over a layer of squash. Place another pasta round on top and spoon over the wild mushrooms. Repeat the layering process until all of the pasta, squash and mushrooms are used up, finishing with the pasta on top. Spoon over the sage butter and garnish with the remaining fresh sage leaves.
