Rehydrate seaweed according to package directions. Rinse well and drain completely in a sieve.
Thinly slice cucumber using the finest setting on a mandoline slicer (or as thin as you possibly can with a sharp knife).
Combine cucumber and rehydrated seaweed in medium bowl.
Combine honey, lemon juice, olive oil, and sesame oil, and add to cucumber and seaweed mixture. Toss to coat.
Add sesame seeds, avocado and mango and gently toss to combine. Serve immediately.
