Cook the sweet potato

• Boil the sweet potato chunks in salted water until completely tender.
• Drain well and mash until smooth, then let cool slightly.

Make the dough

• Add the egg, parmesan and salt to the mashed sweet potato.
• Gradually work in the flour until a soft, non-sticky dough forms.

Shape the gnocchi

• Roll the dough into long ropes on a floured surface.
• Cut into small pieces and press each one with a fork.

Boil the gnocchi

• Cook the gnocchi in salted boiling water.
• Remove them with a slotted spoon as soon as they float.

Brown the butter

• Melt the butter in a frying pan with the sage leaves until golden and fragrant.
• Toss the drained gnocchi in the sage butter and serve with parmesan.