NEW DELHI (Reuters) - As India's capital baked in a heat wave, banker Gaurav Gupta sat down for lunch at a new air-conditioned restaurant, to be greeted by a smiling waiter who took his order for a traditional "thali" meal of flat bread, lentils, vegetables and rice.Nothing unusual, except that the employee, like most of his colleagues, is a convicted murderer serving time in South Asia's largest prison complex."Tihar Food Court" in west Delhi, a rehabilitation effort kicked off by the Tihar prison, opened in the first week of July on an "experimental basis" while awaiting formal clearances. It is sited half a km (0.6 mile) away from prisoners' dormitories.With a spacious interior lined with wooden tables and walls adorned with paintings done by prisoners, the 50-seat restaurant has been praised for the polite behavior of its employees, who were trained by a prestigious nearby hotel management school."The food is average," said Gupta. "But the hygiene factor is really good, very clean. And it's a good thing they are employing prisoners."Restaurant manager Mohammad Asim said there are around 50 customers every day, with each worker paid 74 rupees ($1.20) for the day's work.The vegetarian menu features mostly northern Indian food items, such as samosas, or deep-fried pastry triangles stuffed with spiced potato, and kidney beans with rice. The deluxe thali is the priciest item, costing 150 rupees ($2.50), while samosas are among the cheapest, at 10 rupees (17 cents)."Those who come once to have our food come back again," said Asim, who has spent 14-1/2 years in jail for murder.To be eligible to leave prison and work in the restaurant, inmates must have kept up an "unblemished record" through at least 12 years of imprisonment, besides a high school education.Prisoners eligible to be released within two years are picked for the job, to minimize their temptation to escape. They travel to work by cycle or on foot, as authorities "trust them enough" not to need a security escort.Comments in the visitors' book are mostly encouraging."The food was simply delicious," wrote one guest, Bhoomika Dabas. "The service provided was also commendable ... 10/10 for cleanliness and humble service. Suggestion: include more variety of cuisine."Revenue from the non-profit restaurant, flagged under the TJ's brand of products made by prisoners, is earmarked for prisoner welfare and vocational training, said Sunil Gupta, a spokesman for the Tihar jail.Once notorious for corruption, drug problems and prisoner abuse, the Tihar jail complex has ushered in several reforms, with vocational training and painting featured among the rehabilitation programs offered to its 13,552 inmates.