Preheat the oven to 200 degrees circulating air. Roughly dice the potatoes and onions and chop them well in a blender or hand blender. Then add the remaining ingredients and mix well until a relatively thin dough is formed.
The amount is enough for 12 large muffins (6-cup form). Rinse the silicone mold first with hot and then cold washing-up liquid and fill in the dough. Bake the muffins for 40 to 45 minutes until they are golden yellow. Let cool down for about 10 minutes.