Mushroom, Puy lentil & walnut pie with chive mash

1. Start by making the mash. Place the cubed potatoes in a large pan of cold water, bring to the boil with a generous amount of sea salt, then reduce the heat and simmer for 15-20 minutes, or until tender. Drain well, then mash with the butter, taste for seasoning and stir through the chives. Set aside.

2. Meanwhile, to make the ragù, cook the Puy lentils according to pack instructions, using the vegetable stock instead of water. Drain, reserving the cooking liquid.

3. Heat the oil in a large pan over a medium heat. Add the onion, garlic, carrots and a pinch of salt and sauté for 5 minutes, until softening but not brown. Purée the chestnut mushrooms into a rough paste in a food processor, using some lentil cooking water to help loosen.

4, Add the paprika, walnuts, porcini powder, chopped woodland mushrooms and chestnut mushroom purée to the pan and cook for 20 minutes over a medium heat to dry out a little. Increase the heat to high, add the wine and let it bubble away. Add the bay, tomatoes, the cooked lentils, oregano, chilli flakes and basil and reduce the heat to its lowest setting.

5. Cook for 45 minutes, stirring deeply and thoroughly every few minutes. Taste, season, and taste again. Remove the bay leaves before serving. At this point, spoon ½ into a pie dish. The rest of the filling can be cooled, then chilled or frozen (see tip). Alternatively, double the mash.

6. Preheat the oven to 200°C, gas mark 6. If the mash is a little dry, loosen it with the milk or milk alternative. Pipe or spoon the mash onto the filling. Either way, start at the edges and work your way towards the centre, to avoid pushing the filling out over the sides of the dish. If using, sprinkle the grated Cheddar or alternative, over the top. Bake for 30-35 minutes until golden brown and piping hot throughout (use a knife inserted into the centre to check). Serve with buttered peas and wilted spinach.