Preheat oven to 500 degrees. Stuff 1 tablespoon of crab mixture into each prawn. Place prawns on sheet pan with 2 ounces in water on pan. Cook for approximately 5 minutes.
Meanwhile, bring vinaigrette to a boil. Add cucumbers until slightly wilted. Remove from pan and keep warm. Add peppers, ginger, shallot and garlic and reduce sauce slightly. Add mint and cilantro.
Place cucumber julienne in center of plate. Add prawns in center. Top each prawn with 1 tablespoon of hollandaise. Finish by spooning vinaigrette around plate.