Method

1. Heat the olive oil in a large frying pan over a medium heat. Add the textured vegetable protein and onions and fry, stirring, for about 5 minutes, or until the onions are soft. Add the leek, carrots, celery and broccoli and cover the pan, reduce the heat to low and leave to simmer for 20 minutes, stirring occasionally, or until the vegetables are tender.

2. While the vegetables are cooking, make the mash for the topping. Bring a pan of salted water to the boil. Add the potatoes and boil for 15 minutes, or until very tender. Drain the potatoes well, then put them in a bowl and mash, gradually adding the milk, followed by the butter. Stir in a good handful of the cheese, then taste and adjust the seasoning if necessary.

3. Preheat the oven to 200C/gas 6 and grease a large ovenproof dish.

4. Tip the cooked vegetables into the dish and smooth the surface. Spoon the mashed potatoes on top and sprinkle with the remaining cheese. Place the dish on a baking sheet and bake for 10–15 minutes until the filling is hot and the cheese is melted and golden.