For the dry marinade, crush paprika powder, 1 tablespoon cayenne pepper, garlic powder, sea salt and smoked sea salt finely with a mortar. Put the fried onions in a freezer bag, close it and crumble them finely with the rolling pin. Mix with the spice mixture.
Wash the meat, dab dry and rub with the dry marinade from both sides, cover and leave to cool for approx. 3 hours. For the hamburger buns, stir yeast with 20 g sugar until liquid. Warm the butter and milk. Add 150 ml of water and let it cool down lukewarm. Put 1 tsp. salt, flour and egg in a bowl. Add milk mixture. Add the yeast mixture and immediately knead into an elastic dough with the dough hooks of the hand mixer for 6-8 minutes. Cover and leave to rise in a warm place for about 45 minutes.
For the barbecue sauce, peel and finely dice the shallots and garlic. Place in a pot with Worcestershire sauce and maple syrup and bring to the boil. Let simmer for about 2 minutes. Add ketchup, 2-3 tbsp vinegar, sweet paprika and 1 tbsp cayenne pepper. Let everything simmer for about 10 minutes, stirring from time to time.
In the meantime heat oil in a pan and fry meat for about 4 minutes, turning it over. Place the meat on a baking tray and bake in a preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: see manufacturer) for approx. 6 minutes. Remove meat from the oven. Use two forks or a knife to pluck or cut the meat into small pieces. Remove the sauce from the stove and mix in the meat.
Briefly knead the dough once again on a floured work surface. Form about 6 round rolls from the dough and place them on a baking tray lined with baking paper. Cover and leave to rise for another 20 minutes. Whisk the egg yolk with cream. Brush the rolls with the cream and bake in a preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: see manufacturer) for about 15 minutes. Remove and let cool on a cake rack.
Wash the salad, dab dry and cut into fine strips. Mix 2 tablespoons vinegar, olive oil and sour cream, add chili flakes, salt and pepper and season to taste. Cut the rolls in half horizontally. Heat clarified butter in a frying pan, roast each half while turning. Warm the meat in the sauce. Season salad again with salt, pepper and sugar. Cover the lower halves of the rolls with plenty of meat and salad. Place the lid of the roll on top and serve immediately.