From the same source, a few different streams may flow. And from the same family recipe, a few distinctive versions of a dish may follow.
In the case of the Thye Hong fishball noodle family, different family members running different stalls across Singapore still get yellowtail fish from the same supplier. "We learnt the same method, we use the same fish, but what we cook tastes different," says former hawker Ng Hock Chye, 60.
He is the youngest of five brothers, three of whom have noodle stalls. The eldest brother is no longer selling noodles. The second brother has a Thye Hong fishball noodle stall that is an institution in Ghim Moh Road, where the third brother also has a lor mee stall. The fourth brother sells fishball noodles at Ru Ji Kitchen in Holland Drive.
Thye Hong was started by his two eldest brothers, says Mr Ng. The name was taken from the Thye Hong biscuit factory in Alexandra Road, where the fishball noodle business began about 40 years ago as a street stand before moving to the Ghim Moh food centre in 1977.
Mr Ng learnt the ropes in Ghim Moh before setting up a Thye Hong stall in Bukit Batok East Avenue 4 in 1989. He ran the stall till 2010, when a neck injury put him out of action.
He had to wear a brace on his neck for a year, which made working impossible.
THYE HONG FISHBALL NOODLE
01-53 Block 233 Bukit Batok East Avenue 5
Open: 4am to about 4pm daily, closed on Tuesday
It was around then that his son, Ching Song, now 28, began to take an interest in the business. Under his father's tutelage, Ching Song, who is the youngest of three children, set up shop in Bukit Batok East Avenue 5 in 2012.
Broadly speaking, the Thye Hong method includes making the fishballs by hand, preparing the chilli and mixing the noodles with lard and chilli thoroughly before serving them.
"We use chopsticks to mix the noodles, which is hard work," says the older Mr Ng.
Although the stalls share the same history, long-time patrons are able to taste the difference.
The flavouring is heavier in Ghim Moh. The chilli is more fiery in Holland Drive. The version in Bukit Batok is milder - old-fashioned, even.
Ching Song says he has learnt to make the dish (from $3) the old way by following his father's instructions.
He does not take short cuts such as adding MSG to the soup.
The stall has made a new concession, though. It uses less lard and the dish has a cleaner finish.
Ching Song, who is married with a daughter, is straightforward when he is asked why he is following in his father's footsteps.
"My father raised the three of us by selling fishball noodles and now I have a child to raise."