Players who wish to reside in Taverley Dungeon for extensive periods of time can bring equipment (logs, tinderbox, oily fishing rod and bait) to fish and cook the lava eels to produce food for combat. This is especially true for players given Black demons or Blue dragons as a slayer task.
During the Heroes' Quest, guild-master Achietties will ask players to obtain a cooked lava eel to prove that they are worthy of membership to the Heroes' Guild. Players will then need to visit Gerrant in Port Sarim to learn how to make an oily fishing rod, followed by going to either Taverley Dungeon or the Wilderness Lava Maze to catch an eel.
Oddly, you can cook the lava eel on fire. In real life, lava is much hotter than a simple campfire. This is also stated in the Lava eel's examine information.