Preheat the oven to 170°C circulating heat. Peel sweet potato and cut into small pieces. Cut the cauliflower into small pieces as well. Place on a baking tray covered with baking paper. Brush with olive oil. Season with salt, pepper and ground cumin. Bake in the oven for about 20 minutes.
Meanwhile, finely chop the onion and garlic. Sauté them in a pan with some olive oil. Ground the oat flakes finely in a mixer. Grate the cheese and finely chop the coriander. Take the sweet potato and cauliflower out of the oven and let them cool down briefly. Then mix the cauliflower finely and grind the sweet potato pieces roughly.
Place all the ingredients for the burger patties in a bowl. Mix well and season with cumin, salt & pepper. Let the mixture rest for 10 minutes and then form 4 burger patties of the same size. Fry the patties in a covered pan with olive oil until golden brown. (Optional) Bake the patties in the oven for another 10 minutes at 170°C circulating heat.
Beetroot chips & Dip
Cut the beetroot into thin slices using a mandolin and place on a baking tray. Then drizzle with olive oil and apple vinegar and season with salt. Bake for 15 minutes at 190°C until crispy, remove and put aside to cool. For the dip, mix sour cream, yoghurt and chopped chives. Season with salt and pepper.
Cut the burger buns in half and toast them. Spread the corn salad and hummus on the bottom half of the bun, cover with a hot fried burger patty and finish with sour cream dip, 4-5 beetroot chips, cress and the top half of the bun. Serve with the remaining beetroot chips and the sour cream dip as a side dish.