Islamic Restaurant in North Bridge Road is multi-generational in many ways.
The 94-year-old restaurant is headed by third-generation owner, Mr Kalil A. Wahab, 54, and those running the kitchen are also from families who have worked in the restaurant for decades.
Four of its cooks, who are in their 40s, have been working in the restaurant for more than 20 years, following in the footsteps of their fathers and grandfathers.
The cooks are from Enangudi, a village in Tamil Nadu in India, the hometown of the founder of this restaurant, Mr M. Abdul Rahiman, who came to Singapore in 1900.
Mr Kalil's nephew, Mr Irfan Akram, 26, the restaurant's head of business development, credits these "family-line cooks" for preserving the taste of its signature nasi briyani for more than nine decades.
He says: "Our cooks feel a sense of ownership for the recipe, so they are motivated to ensure its consistency."
With up to 200 servings of nasi briyani sold a day, he says that 90 per cent of the business is dependent on its Turkish-Indian version of the dish.
For Singapore Restaurant Month, it has come up with fish briyani, which will be served from July 17 to Aug 2.
He says: "We want more people, especially the younger generation who seem to go to only cafes these days, to know about this dish, aside from our stars, the mutton and chicken versions."
Priced at $12, the fish briyani uses locally sourced mackerel and comes with sambal-topped hard-boiled eggs.
The restaurant prides itself as the first to serve nasi briyani here in 1921.
Mr M. Abdul Rahiman, who was head chef for the prominent Alsagoff family, distributed packets of food to the needy in Jalan Sultan during the Japanese Occupation.
That rewarding experience spurred him to start Islamic Restaurant across four shophouses in North Bridge Road, where it stood for 86 years. In 2008, it moved to its current premises down the road.
Mr Kalil, who has been working there since 1978, recalls that Islamic Restaurant was regarded as a "five-star wedding venue" in the Muslim community from the 1950s to the 1980s.
He says: "We had a space that could fit up to 400 people. I spent up to 12 hours daily cooking the dish over charcoal stoves."
He adds that the winning nasi briyani is not as rich and fiery as the Indian version, and draws on Middle Eastern influences for its secret blend of about 25 spices for the meat marinade.
A serving of nasi briyani started from $1 in the 1970s. It now starts at $9 a serving.
Islamic Restaurant's nasi briyani is popular among local politicians and regional dignitaries.
Mr Kalil says he drove across the Causeway to deliver 10 packets of nasi briyani to a top Malaysian politican three years ago.
The restaurant also does catering and has been doing so since it started cooking for events at the British High Commission and for a buffet lunch at the Padang for British expatriates in the 1920s.
One of its milestones was catering for a wedding attended by 10,000 people in the Singapore Cricket Club four years ago.
Even though it is still popular, the restaurant has continued to evolve.
It offers island-wide briyani delivery service, and has a cooking studio which offers lessons in Malay and Mediterranean cooking.
Besides promoting the restaurant on food service websites such as Foodpanda and Chope, Mr Irfan hopes to franchise the business by this year and set up five outlets soon.
He says: "It was my grandfather's vision to have branches of Islamic Restaurant around Singapore, and I want to fulfil his dream."