60g fresh morels, (or dried morels, rehydrated in hot water)
30ml white wine
300ml double cream
100ml vegetable (or chicken) stock
First make the pasta. Place the flour in a mound on a clean work surface and make a hollow 'well' in the centre of the flour. Place the egg yolks, salt and olive oil in the centre of the well along with 15-20 ml of cold water. Use a fork, to mix the eggs, water and oil together with the flour until well incorporated, add more water gradually as required. Turn the dough out onto a clean, floured work surface and knead until it is smooth and elastic (this will take about 10-15 minutes). Wrap the dough in cling film and place in the fridge to rest for one hour.
Next make the filling. Melt the butter in a large heavy pan over a medium heat and add the shallots and garlic. Sweat for 5 minutes, then add mushrooms and cook for a further 10 minutes until the liquid has evaporated. Add the white wine and herbs and season with salt and pepper to taste. Then gently stir in the Parmesan cheese and allow the mixture to cool.
Remove pasta dough from the fridge and cut a small strip from the dough and use a pasta machine to pass the dough through the first setting (thickest) at least 3-4 times. Set the pasta machine to setting number 3 and pass through another 3-4 times, dusting the machine and dough with a little flour to prevent it sticking. Change the pasta machine setting to no. 5 and pass the dough through 3-4 times until dough is thin. At this point the dough should be roughly 1 metre long.
Place on a lightly floured work surface and using a 10 cm round cutter, cut 8 circles from the dough. Place a spoonful of the cooled mushroom mixture in the centre of 4 of the discs ensuring there is at least an inch of space between and around each spoonful. Lightly brush the edges with water and place the remaining discs on top of each raviolo sealing the edges well and set aside.
In a small saucepan, place the butter, shallots, garlic and thyme leaves and sweat over a low to medium heat for 5 minutes. Add the morels and cook for a further 2-3 minutes. Add white wine and reduce a little. Pour in the cream and vegetable stock and season with salt and pepper and then reduce the mixture by a quarter. Remove from heat and blend in a food processor until smooth. Pass the sauce through a strainer into a clean saucepan and keep warm until serving (If the sauce needs further thinning add a little more stock)
Peel and shave the base of the asparagus and place in a pot of boiling water for three minutes. Strain and plunge the asparagus into iced water to stop the cooking process and set aside.
When ready to serve, bring a large pot of lightly salted water to the boil and place the 4 ravioli in the boiling water and cook until they float to the surface. Remove immediately with a slotted spoon and place on a plate lined with a clean tea towel or kitchen paper to absorb the excess water.
To serve, place one raviolo in the centre of a soup plate and use a hand blender to whip the morel sauce. Spoon some of the resulting foam over the pasta and place two spears of the asparagus on top and garnish with shavings of fresh Parmesan.