For the BBQ sauce, cut the chilli pepper lengthwise, remove the seeds, wash and chop finely. Mix ketchup, chilli, brown sugar, 1 tablespoon vinegar, coffee, whiskey and honey in a pot. Bring to the boil and boil down for about 10 minutes until thick.
Finely dice the cucumbers for the relish. Peel and finely dice shallots. Bring both to the boil with vinegar and brown sugar in a pot while stirring and boil down for about 10 minutes. Season to taste with salt.
Fry the bacon in a pan without fat until crispy. Place on kitchen paper. Dab steaks dry and cut the fat edge crosswise. Heat 2 tablespoons of oil in a large frying pan. Fry the steaks in it for about 1 minute on each side.
Season with salt and pepper. Turn down to medium heat. Then continue to fry for 2-3 minutes on each side for one pink steak (medium). Wrap the finished steaks in foil and let them rest for about 5 minutes.
Preheat the grill of the oven. Line a baking tray with baking paper. Peel onions and cut them into thin rings. Cut open rolls and roast the flat sides briefly in a pan without fat.
Cut off the fat edge of the steaks if necessary. Cut the steaks into thin slices. Spread a thin layer of BBQ sauce on the lower roll halves. Cover with relish and steak slices and 1 slice of cheddar cheese each.
Bake the halves under the hot grill for 1-2 minutes until the cheese has melted slightly. Remove.
Cover with onions and bacon and drizzle some BBQ sauce over it. Place the top halves of the rolls on top. Add the rest of the relish and BBQ sauce. Serve with French fries.