Toss the sweet potatoes with some oil and salt. Place on a sheet pan and roast at 350 for about an hour until tender. Allow to cool and peel.
Mash the sweet potatoes and stir in the egg. Add a pinch of salt. Add the flour and stir well, then start to knead when it becomes solid. Knead for about 5 minutes, adding flour as needed if it feels too wet or sticky, to form the dough.
Take about a tablespoon worth of dough and flatten it in your palm. Place a mozzarella pearl in the center and wrap the dough around the cheese. Roll around between your palms to seal. Place on a floured surface.
Bring water to a boil and season with salt
Meanwhile, melt the butter on high heat and add the mushrooms. Cook about 5 minutes stirring often to brown the mushrooms. Stir in the kale and cook 2 minutes. Season with salt and pepper. Turn heat to low and stir in the garlic.
Drop the gnocchi into the boiling water and cook about 3 -5 minutes, keeping a close eye on them. If you see any cheese leak out, strain them immediately!
Strain the gnocchi and put them directly into the pot with the mushrooms and kale. Cook another 3 minutes. Serve!
