As you might expect from the number of fishing boats visible in all the ports, Iki offers a wide range of seafood with the local specialities being ika (squid) and uni (sea urchin). The bright lights of the fishing vessels that can be seen most nights are designed to attract squid whereas the sea urchin is collected from the island shores (to do so you need to have an official license). Iki beef, though somewhat pricey, is expensive for a reason - it's really good!
Umeshima is well known on the island for it's quality food and secret yakiniku sauce. The staff are friendly, the location is convenient and the family platter is recommended (if you don't like something on the platter they'll often change it for another item if you tell them at the time of ordering). As the restaurant can get quite busy, it's recommended to make a reservation.
Location: Ashibe (opposite from ferry terminal, next to Daiei)
Price: 2-4000yen per person
Unimeshi Shokudo Harahoge うにめし食堂はらほげ
Specialises in Iki's uni (sea urchin but has plenty on the menu for those who think that sea urchin should be in the sea and not on a plate.
Location: Ashibe (near Harahoge Jizo and Sakyobana)
The jewel in the crown of Iki sushi and sashimi. As you would expect on an island, the fish is ultra fresh and superbly presented.
Location: Ashibe (next to Shoni park and only 2 minutes drive from Daiei)