Mix the mayonnaise and ketchup with the liquid smoke and season with coarsely ground pepper from the mill.
Fry the bacon in a pan in a little oil. Remove from the pan and place on kitchen paper to drain.
Fry the onions over medium heat, add the sugar and caramelize the onions in them until they have a nice brown color. Use more sugar if necessary.
Cut the burger buns open and heat them up in the oven, in a pan, on the grill or in the toaster.
Brush both halves of the bun with a little burger sauce and top the lower half with iceberg lettuce, 2 slices of tomatoes and the bacon.
Shape 200 g minced beef into a burger patty using a burger press or by hand. Don`t forget to make a depression in the middle so that the meat doesn`t lose its shape when roasting or grilling.
Fry or grill the patties on one side for about 4 minutes. Then turn it over, season with salt and pepper and fry again for just under 3 minutes. Then place the onions on top of the meat and cover each patty with a slice of cheddar cheese. Now put the lid on the pan for about 1 minute so that the cheese can melt.
Place the finished patties on the already covered bun halves, put the lid on and enjoy.