In a small bowl, combine olive oil, lemon juice, parsley, salt and pepper.
Set aside for no more than 30 minutes or the lemon juice will yellow the parsley. 3-4 cups of water to a boil in a saucepan large enough to fit the fish pieces comfortable. Holding the fish with a slotted spoon or skimmer, lower gently into the pan and bring the water back to a boil. Reduce the heat to very low and poach the fish for 3-4 minutes until barely cooked through. Lift the fish from the water, drain thoroughly and arrange each fillet on a warm plate. Spoon the sauce over the fish serve immediately.