Celebrity chef Steffen Henssler runs a sushi restaurant in Hamburg with his father. Due to rising energy costs, the duo has decided to charge their guests an energy flat rate.

This has caused trouble, which some have made public on the net. The costs would not only appear on the invoice, as a look at the menu shows. "Nothing is hidden! There is an explanation visible on the menus and there is a large sign on the front door," says HensSler.