Place the sweet potato whole on a plate and prick it with a knife or fork. Bake it in the microwave for 10 minutes on the highest setting. If you don't have a microwave, bake the potato in the oven for 50 minutes. When the sweet potato is soft, you can move on.
Peel the potato and put it in a bowl. Mash them with a fork. Let it cool for 2-3 minutes. In the meantime you can grate the parmesan very finely.
Add the Parmesan cheese, salt and nutmeg to the sweet potato mixture. Mix the ingredients thoroughly before slowly adding the flour. Caution: Do not knead too long, otherwise the dough will be really sticky! Chill the dough for 15 minutes. Meanwhile, bring a large pot of salted water to a boil.
Flour the work surface and form 2-3 rolls from the dough. Cut 1-2 cm pieces from the roll and form balls from them.
Roll the balls over the tip of the forks.
Turn down the boiling water and wait until it stops bubbling so much. Put the sweet potato gnocchi in the hot water, put the lid on the pot and wait until the gnocchi float to the surface after about 3 minutes.
Take them out of the water and let them drain.
For the garnish
Fry the gnocchi in a pan with 1 tablespoon of olive oil. When they are hot, take them out of the pan.
Chop onion, garlic and mushrooms. Fry garlic and onion with olive oil.
Add the mushrooms. Fry them hot and mix in the lemon juice. Season with salt and pepper.
Stir in the gnocchi and at the very end the parsley.