Preheat the oven to 200°C.
Peel sweet potatoes, cut into cubes and cook in lightly salted water until tender.
Meanwhile, shred or very thinly slice the cabbage.
Take the cooked sweet potato cubes out of the pan with a slotted spoon, then add the cabbage to the water and blanch for 3 minutes. Drain, leave to cool.
Heat the oil in a frying pan, add the fennel, garlic and paprika and fry for a few seconds, then add the sweet potato cubes.
Mash roughly with a fork - leave it a bit lumpy!
Add the cabbage. Stir and let it cool.
Using your hands form 4-6 balls, then slightly press them between your palms.
Put the cakes onto a lined baking tray, sprinkle with grated cheese and cook for about 10 to 15 minutes until the cheese melted and the cakes are golden brown.
Serve warm.