Preheat oven at 350 degrees.
On a long piece of parchment paper, place cabbage then top with cod and chopped leeks.
Place on baking sheet and place in oven for 20 minutes.
Remove from oven and let cool for a few minutes.
Carefully unwrap paper and place cooked ingredients in blender or food processor. Add water and puree.
Serve immediately or freeze for up to 3 months.
*Use all organic ingredients if possible.