In a small bowl, combine the mayonnaise with the lime zest, lime juice, salt and pepper. Cover with cling film and set aside until required.
In a second bowl, combine the lemon juice and the olive oil and add the shredded iceberg lettuce, toss to coat the leaves.
Half fill a teacup or a glass with some iceberg lettuce, then add a good tablespoonful of fresh crabmeat and a dollop of lime mayonnaise.
Store in the fridge for a few hours and Serve with a wedge of lime.