Peel the sweet potatoes, wash the zucchini and remove the ends. Grate both coarsely and mix with the eggs, 50 g sour cream, pepper and breadcrumbs.

Toast the cashew nuts in a non-stick pan, roughly chop them and fold them into the batter.

Melt the butter in a pan. Pour 1 tablespoon of buffer dough into the pan for each buffer and flatten it a little. Fry the buffers over a moderate heat until golden yellow. It is best to keep the buffers warm in the oven at 50 ° C.

For the dip: pluck the coriander leaves from the stems and roughly chop. Mix with the remaining sour cream and season with salt and pepper.

Divide the buffers on plates and serve with the dip.