Cooked crab meat can be made by cooking crab meat, dropped by crabs. Cooking the crab meat requires level 21 Cooking, and will give 100 Cooking experience. Cooked crab meat provides 5 bites healing for 2 hitpoints each. It is used in Recipe for Disaster to make a cooked fishcake to give to Pirate Pete. The small amounts of hitpoints per bite it gives can also be used to "fine tune" the hitpoints of someone using Dharok the Wretched's equipment. However, it is not recommended for general healing as tuna is one-bite, heals just as much and costs about half as much.
Subquest of Recipe for Disaster