Bring a large pot of water to a boil and add the rehydrated sea cucumbers. Boil the sea cucumbers for 45-60 minutes, until they are tender. The sea cucumbers should have a good bounce and not feel too firm.
Remove the sea cucumbers from the boiling water and let drain. Once it's cool enough to touch, slice the sea cucumbers to ½-inch thick pieces.
Arrange on a plate and let chill in the refrigerator for 30 minutes.
Serve cold with a side of soy sauce and wasabi for dipping!