To prepare the leeks, cut off the really dark part and keep to use for another time.

Split the leek lengthwise and slice thinly. Place the leaks in a container of cool water.

Agitate to dislodge the dirt or sand; take out leeks with a slotted spoon. I do this at least twice with clean water. 

Cut 2 pieces of foil big enough to accommodate 1 fish fillet each and the rest of the ingredients.

Place half of the leeks on each piece of foil, then the salmon-skin side down-and add the other items.

Seal the foil with the seam on top.

Cook over an open flame - this is great for camping. Cooking time depends on the source of heat but averages 15 min.