Peel the potatoes and cut into fine julienne using a mandolin (or alternatively grate coarsely).
Place potatoes into a bowl of cold water to soak for 3 minutes (I used my salad spinner), then rinse in a colander until the water runs clear to remove the starch.
Preheat waffle iron.
If you have a salad spinner use it to dry the potato and finish off by patting with kitchen paper. Otherwise wrap potato in a clean towel and squeeze to remove all the moisture and then pat dry.
Place the potato, spring onion, melted butter, rapeseed oil and seasoning into a bowl and mix well.
Place half the mixture into the waffle iron and cook until golden brown and potato tender (about 8 minutes).
Repeat with the other half of the mixture.
Serve waffles whole with a fried or poached egg (serves 2) or cut up into sections and served as a side dish (serves 2 - 4).