1 1/2 lb Freshwater fish -

      1 x  Perch, bass, trout - diced

    1/2 c  Tomato, sliced

    1/4 c  Onion, sliced thin

    1/2 t  Freshly ground black pepper

    1/2 t  Salt, or to taste

    1/2 t  Thyme

      2 ea Bay leaves

      2 ea Mashan leaves -OR-

      2 ea Sheets aluminum foil

  Mix the diced fish, tomato, onion, black pepper, salt, thyme and bay
  leaves together.  Put the mixture in the middle of the leaves or foil,
  fold over each half to the center, then fold over each end toward the
  middle.
  Steam the packages in a Chinese-style steamer over hot water over
  moderate heat for 30 minutes.
  Unwrap and serve hot in the wrappers.
  Variation:  This procedure works very well if you substitute a 1-pound
  fillet of an ocean fish shch as scrod, sea bass, mackerel, or whatever
  is one's personal preference.
  Source: False Tongues and Sunday Bread by Copeland Marks