Start with ANY greens, fruits and vegetables you can find. An example would include, but not be limited to; carrots, broccoli, yams, oranges, apples, Romaine lettuce, etc. Put all the above in a blender or food processor. Slowly add shrimp, crab legs (both with shells), and/or smelt. Do not use any fish that would contain high levels of oils, like herring or mackeral. Blend mixture as fine as possible.
Add liquid vitamins or crushed tablets, you can also add Selco or Selcon. The mixture should have the consistancy of mud. Add some liquid to thin it up if it appears to thick, carrot or sweet potato juice works well for this purpose as it is high in vitamin content. You can also use clam juice or water.
Next: Boil 100-150ml of water and add the same amount of unflavored gelatin. Mix the gelatin and vegetable mixture together pour the resulting mixture into a rectangle pan and allow to cool. You can place the mixture in the freezer but be sure to score the mixture before it is completely hardened, to make it easier to separate later.
After the mixture is frozen you can separate the pieces and place them in freezer bags for use as needed.