Shrimp sambal, reconstituted milk, and fried noodles bubble away in a pot, filling the air with the aroma of laksa, Singapore’s beloved noodle soup. For the cooks working in careful silence, the smell is a reminder of life outside of the prison they are stuck in, and it is hard-won: To make the dish, one man lit a flame on a candle made of his T-shirt and a melted-down food tray; another purchased the can of sambal from the commissary before scraping it open against the concrete wall; while yet another sacrificed the noodles of his paltry prison lunch.
Source: The Underground Cooks of Singapore’s Prisons – Gastro Obscura
In the 1970s and 80s, when the guards stepped away, the pots and flames came out.