Saigon Combo [Photo provided to China Daily]

Chu says that over the years, Vietnamese food has evolved and changed to such an extent that most people are often not aware of the original recipe.

But he adds that while the restaurants are not afraid to evolve and modernize, they will never compromise by adding ingredients that are not Vietnamese.

The food at Saigon Mama is a blend of northern and southern Vietnamese food, and the restaurant's expansive menu features many items that diners may not see elsewhere, from various pho noodles to sandwiches and salads.

He says that many of the ingredients are homemade, such as the hams and the pate used in sandwiches, and the sauces.

Chu also says that his restaurants mainly use ingredients that are either imported from Vietnam or from other countries.