Put all the ingredients in the mixer and blend to a smooth dough.
Place the dough in a vacuum bag and seal. Leave to rest in the fridge for at least 30 minutes.
Chop the mushrooms and onions into rough pieces, sweat them on a low heat in a pressure cooker (lid off).
Add a few pinches of salt and pour on the water. Put the lid on the pressure cooker, seal and let it cook for
45 minutes. Strain the broth and add fermented porcini mushrooms and miso. Reduce if necessary.
Dry any mushrooms left over from cooking. Add truffle butter just before serving.
Pick the thyme and finely chop the mushrooms and onions. Fry onion and thyme on medium heat until nicely browned. Add the white wine and bring to a boil. Reduce the heat, add the grated cheese and double cream and simmer to a creamy texture. Season with salt and pepper.
Peel the onions and cut them in half. Brown butter and fry the onions golden with the cut side facing down in the frying pan.
Add sugar, vinegar, thyme and salt, cover with a lid and simmer for 1.5 minutes, let it cool down.
Melt the butter in a pot.
Mix the hazelnuts with the melted butter to make a nice hazelnut butter.
Clean the mushrooms according to instruction. Fry in a dry pan to evaporate the liquid in the mushrooms. Add butter and crushed garlic just before serving. Season with salt and pepper
Roll out the pasta dough on a pasta machine to the desired thickness. Punch out the dough with a cookie cutter and distribute on the filling. Fold the pasta into tortellini as shown. Place the tortellini on a floured sheet and allow to dry for about 40 minutes.
Just prior to serving: Cook the pasta in plenty of salted water before serving.
Deglaze the pan with hazelnut butter, garlic and sage and a little pasta water.