Heat the oven to 200C/180C fan/ gas 6 and toss the squash with 2 tbsp of the olive oil. Tip into a roasting tin and cook for 30 mins, turning halfway, until cooked through and golden at the edges. Tip into a bowl.

Put the porcini mushrooms in a small heatproof bowl, cover with boiling water and soak for 10 mins before scooping out and finely chopping. Reserve the soaking liquid.

Heat the remaining 2 tbsp oil in a non-stick frying pan and cook the button and porcini mushrooms and the onion for 10-15 mins until the liquid from the mushrooms has evaporated and the veg has started to caramelise. Tip in the garlic and rosemary and cook for 1 min more. Tip into the bowl with squash and add the breadcrumbs, lentils and all the nuts. Season, mix well and taste for seasoning. Add 50ml of the porcini soaking liquid – you want the mixture to be moist but not wet. Use a fork to mash the everything together – you want it to come together almost as a dough, not separate components.

Line a 900g loaf tin with a long strip of baking parchment. Spoon half of the butternut squash mixture into the bottom of the tin, pressing to prevent any gaps. Lay the courgette slices in an even layer on top, then add a layer of roasted red peppers and finally the remaining squash mixture, pressing again. Leave to cool completely, then wrap tightly. Will keep frozen for up to three months.

Heat the oven to 190C/170C fan/ gas 5. Unwrap and bake the nut roast from frozen for 1 hr, or until a small knife slides through easily and it is piping hot in the centre.

For the spiced nut topping, tip all of the nuts onto a baking tray, toss with a little salt and the spices, and bake in the oven along with the roast for 8 mins until browned slightly and smelling toasty. Put the caster sugar into a small pan with 75ml water and heat until the sugar has melted. Tip the nuts into a bowl and toss with the sugar syrup, then return to the baking tray and bake for 10 mins more until sticky. Turn the roast out onto a platter or board and top with the spiced nuts and the parsley.