Sweet Potato Gnocchi with Wild Garlic and Sage Pesto

lbs (1 kg) sweet potatoes

ricotta

parmesan

salt

fresh ground black pepper

grated nutmeg

egg

plain flour, plus more for shaping

fresh sage leaves

large basil leaves

(~100 g) packed wild garlic leaves (see notes)

large pinch of salt

olive oil (see notes)

cashews (, almonds or walnuts)

juice of 1/2 lemon

To serve:

knob of butter or a splash of oil

Shredded basil and shaved Parmesan