For the cashew béchamel: Soak the raw cashews overnight with filtered water. 8 hours later, rinse and drain. Using a high speed blender, blend the cashews with 200 ml-250 ml filtered water until smooth. Add 1 pinch nutmeg, and salt and pepper to taste.
Combine the teff flour, brown rice flour, sorghum flour and tapioca starch together in mixing bowl, stir well.
For the roasted shiitake stems: Peel the stems off the shiitake heads and reserve the heads for final part of the dish. Deep fry the shiitake stems in oil at 170°C for 3 minutes until golden brown. Chop them into small pieces. Place in an oven to seal off the excess liquid at 160°C for 5-8 minutes. Cool.
Place the potatoes in boiling water and boil for 20-25 minutes until tender. Cool off and peel. Mash potato flesh in bowl using a fork or bare hands.
Create a well using teff flour mix either on working table or in bowl. Pinch the mashed potatoes with flour to combine. Add the nutritional yeast and shiitake stems and salt and pepper. If the dough feels dry, add a little water to combine but do not over hydrate the dough.
Dust a baking sheet with teff flour.
Roll the dough into logs on floured surface and cut them into 2 cm pieces. Roll each piece towards the back of a fork to create dents in the gnocchi. Place on a baking sheet.
Prepare a large stockpot with salted water. Bring to a boil.
Boil the gnocchi in batches for about 5-7 minutes or until they float to the surface.
Remove the gnocchi with a slotted spoon and cook with either pasta sauce or pan fry with extra nutritional yeast and sage.