1

Preheat the oven to 200°C, fan 180°C, gas mark 6 and put the cauliflower on a baking tray. Mist with cooking spray, season and roast for 55 minutes. Remove from the oven and let cool.

2

Meanwhile, put the dried mushrooms in a heatproof jug with 200ml boiling water and let soak for 10 minutes.

3

Mist a nonstick pan with cooking spray and fry the onion over medium heat for 6-8 minutes. Stir in the chestnut mushrooms and cook for 15 minutes. Add the mace, garlic and thyme, and cook for 2 minutes, then transfer half the mixture to a bowl and the rest to a food processor. Strain the rehydrated mushrooms, reserving the liquid, then add them to the food processor with the chestnuts. Pulse to a purée, then stir it into the remaining mushroom filling. Season and set aside to cool. Press the pâté over the cauliflower to coat. Chill in the fridge for 30 minutes.

4

Roll the pastry out to a thin square. Brush the cauliflower with a little of the egg, then put it in the centre of the pastry, pâté-side down. Bring the pastry up and around the sides, pinching it at the base to seal. Put, seal-side down, onto a baking sheet lined with baking paper and chill in the fridge for 30 minutes.

5

Preheat the oven to 200°C, fan 180°C, gas mark 6. Brush the pastry with a little egg, then bake for 25 minutes. Brush with more egg and press the cheese over the top. Bake for 15 minutes.

6

To make a mushroom gravy, mix the gravy granules with the reserved mushroom soaking liquid and 350ml water in a pan. Heat gently over a medium heat, stirring, until thickened.

7

Cut the wellington into wedges, then serve with the gravy.