Smoked Haddock with Peas

Smoked haddock and peas go together like ducks and water, or in the words of the song, love and marriage and a horse and carriage. What I am trying to say is that they are naturals together. Instead of little gem you could use small heads of cos or romaine lettuce. The bitterness of grilled trevisse, if available, would also work very well with this dish.