200 g Puy Lentils
1 Bay leaf
700 ml of light vegetable stock or water
1 Large red onion, sliced
4 x 150 g cod fillets (skinned and boned)
50 g Watercress
For the dressing
150 g of plain yoghurt
Small bunch of fresh chopped chives
Finely grated zest and juice of one lemon (or two limes)
1 red chilli, de-seeded and chopped very finely
Salt and freshly ground black pepper
Preheat the over to 220C/gas 7. Place the lentils and bay leaf in a saucepan with the stock or water and bring to the boil. Partially covered with a lid, and simmer for 30 minutes, or until the lentils are just tender. Drain away any excess liquid and discard the bay leaf. Season the lentils with a little salt and pepper.
While the lentils are cooking, spread the onion on a lightly greased baking tray, and roast for 10 minutes. Sit the cod on top and roast for a further 10 minutes, until the cod starts to flake easily.
Mix the lentils with the watercress and the red onion, divide between 4 warmed plates, and top with the cod. Combine all the dressing ingredients and drizzle over the cod to serve.