Pierce the sweet potatoes a few times with a fork. Microwave potatoes on HIGH for 10 minutes or until soft. Remove the skins from the flesh and add to a food processor.Puree the sweet potato until very smooth. Add the flours, salt and nutmeg. Pulse until just mixed. The dough should be soft but not sticky and easy to handle. If needed, add more flour, 1 tablespoon at a time till dough is just right. Make a large ball of dough and place onto a well-floured work surface. Divide the dough into 4 portions. Roll each out into a snake shape, 3/4-inch thick. Use a knife to cut the snakes into 3/4-inch pieces. If desired, shape gnocchi with tines of a fork to make traditional grooves across the back. Place formed gnocchi on a floured baking sheet, leaving space between the pieces. Let them sit to dry for up to 1 hour, or cover tightly and refrigerate for up to 1 day.In a large saucepan, bring the vegetable broth to a rolling boil. Add the gnocchi and cook a small batch at a time. Gnocchi are cooked when they float to the top of the pot. Remove from hot broth with a slotted spoon into a bowl.
TIP: Serve with a butter sauce sprinkled with pine nuts and nutmeg.