Preheat the oven to 180 degrees Celsius (356 degrees Fahrenheit) fan.
Place each fillet on baking paper with the skin side down.
Mix orange juice, mustard, olive oil and spices and sprinkle it over the fillets.
Pull the sides of the baking paper up and twist the edges together to make individual packets.
Add salsa under the fish and garnish with whole watercress, dill or basil.
Place the packets on a baking sheet and bake in the oven for 10 minutes, until the fish is done.
The fish is done when it 'flakes easily' when you press it with a knife.
Heat the lentils according to packaging instructions.
Then mix with orange juice, remaining oil, watercress, herbs and spices.
Distribute the lentils and top each with a fillet. Add some of the cooking juices left in the paper over the fish.