The US president slipped away from his hectic Vietnam visit on Monday night to sample the dish with Anthony Bourdain, a chef and food critic who fronts a travel show about hidden culinary gems around the world.
While 54-year-old restaurant owner Nguyen Thi Lien knew a foreign television crew was on the way, she had no idea they would be bringing a very special guest.
US Secret Service and local police closed down the streets surrounding Bun Cha Huong Lien eatery on Monday evening.
A large crowd gathered outside the restaurant, letting out a cheer as Obama exited.
Surrounded by a coterie of bodyguards, he stopped to greet excited locals, many capturing the moment on their phones, before being whisked away in his limousine.
Click below to watch the video….