Susilo uses blacktip reef sharks that are less than 4 meters (13 feet) long for his dishes and buys his daily supply from local fishermen in Bali, where most of the sharks caught are too small for restaurants selling fin soup.
Most customers come to Pak Item for the shark, which is considered as a cheap source of protein.
"This is my first visit to this restaurant. It tastes good," said A. Teng, 46, an Indonesian who was tucking into shark stew.
But not everyone is impressed by Susilo's efforts.
Indonesian environmentalists have protested against the killing of sharks and are working to draft legislation to protect the big fish.
Indonesia is considered one of the main culprits when it comes to overfishing sharks and World Wide Fund for Nature (WWF) Indonesia official Dewi Satriani said even low-value sharks were being discarded at sea, either whole or with fins removed.
"Indonesia has formally ratified the International Trade in Endangered Species of Wild Flora and Fauna (CITES) pact, therefore those activities should be limited," said Satriani.
She added some countries, including Indonesia, did not report volumes of their catch.
"Indonesia is the world leading shark fishing nation. But this country is not on the list of 20 biggest exporters. This is strange, Indonesia catches most sharks but we have never recorded shark as our commodity," said Satriani.
Sharks, which inhabit all of the world's oceans, are particularly vulnerable to overfishing because they have long life cycles and reproduce slowly.
