Cook baby potatoes in boiling salted water until just tender, about 15 minutes. Drain and set aside to cool. When cooled, quarter potatoes.
Mix mayonnaise with chipotle sauce, lemon or lime juice, coriander (cilantro) and tomatoes.
Remove and shred crayfish meat.
Fold crayfish meat and potatoes through flavoured mayonnaise. Season with salt and freshly ground black pepper to taste. Chill until ready to serve.
Remove a few outer leaves of the iceberg lettuce and slice off the stem, then cut lettuce in half straight down the middle. Separate lettuce leaves into individual lettuce ‘cups’ (if a large cup, cut in half to make two smaller cups). Set 12-14 lettuce cups aside.
To serve, place a spoonful of crayfish potato salad in each lettuce cup and serve on a big platter.