The singer stunned onlookers at the Penn Tandoori eatery in his home city of Wolverhampton, England by turning up with his family, and the group ate food including shish kebab starters, chicken tikka bhuna with rice and naan bread.
Manager Jay Uddin says, "He pre-booked about two weeks in advance for the dinner and they came last Christmas as well, so it's become a bit of a tradition with them now.
"Liam's a regular and he used to visit the restaurant lots with his parents before he became famous. He loves his chicken tikka bhuna.
"There were quite a few fans in the restaurant and everyone recognised him so after his meal was finished, they asked him to take pictures, which he was happy to do.
"He might be a millionaire but I think his dad might have paid for it. No matter how famous you are, I think we all like to let mum and dad pay. I think he was just enjoying taking a break from fame and enjoying a meal with his family."