- Preheat the oven to 180°C/gas 4. Add the oil to a saucepan then add the onions and mushrooms and cook for 3 minutes.
- Sprinkle with the flour, covering evenly.
- Gradually stir in the stock. Add the lentils and yogurt.
- Place the vegetable and lentil mix into a shallow ovenproof dish, and place the cod on top.
- Bake for 15 minutes and serve with parsley and freshly ground black pepper.
- Most firm fish is ideal for this dish – try coley, salmon or haddock.