As Muslims around the world celebrate Eid al-Fitr to mark the end of the fasting month, thousands of migrant workers in Singapore have had to spend the holiday in quarantine because of outbreaks of the novel coronavirus in their dormitories.

To cheer them up, Singaporean businessman Dushyant Kumar, his wife and a team of chefs cooked up a giant biryani for a Sunday evening Eid feast for at least 600 migrants.

Kumar used a family recipe for the South Asian rice dish often eaten during festive occasions.

"Usually, if they are with their family, they will get to enjoy these kinds of dishes, because everyone will cook and eat, but here these guys are alone," said Kumar, in between tasting the dish being prepared in big cooking pots at the kitchen of a restaurant.

There are about 300,000 foreign labourers in Singapore, most of them from Bangladesh, China and India, and most staying in purpose-built dormitories, in rooms with bunks for 12 to 20 men.

"So we want to make sure they don't feel left out," said Kumar, whose imitative is supported by funds from donors and a non-governmental organisation.

"The smile on their face gives you a lot of satisfaction," said Kumar, who has been overseeing the delivery of more than 1,000 meals a day to migrants in quarantine since early April.

The government has said employers are required to provide sufficient food for workers during this lockdown, but it is also working with charity groups to make up any shortfalls.

Singapore has had more than 30,000 COVID-19 cases, one of the highest tallies in Asia, with the vast majority of infections among migrant workers in their dormitory accommodation.