the butter in a frying pan measuring about
20cm wide, then fry the onions for 5-10 mins
until softened. Sprinkle over the smoked
paprika, then cook for 2 mins more.
While the onions are cooking, coarsely
grate the potatoes. Tip them into a clean
tea towel, then squeeze out as much starchy
water as possible. Add the potato to the
onions with 150ml water, then cook until the
water has evaporated and the potato has
slightly softened and is starting to colour.
Use a fish slice to press the potatoes down,
then cook for a further 15 mins until crisp.
Carefully flip the cake over, then cook on
the other side until crisp for about 15 mins.
Meanwhile, place the cheese on top so it
melts slightly while the bottom crisps up.
Cut into wedges to serve.