Preheat the oven to 200C/400F/gas 6. Half the squash and pop on a baking tray with a drizzle of olive oil, then roast in the oven for 30 minutes, or until golden.

While the squash is roasting, thoroughly rinse the walnut pieces and sunflower seeds, then spread them on a baking tray. Roast alongside the squash for the last 5 minutes.

Allow the tray of nuts and seeds to cool a little before putting them in a food processor. For a fine mix, process the nuts on their own. Using a dessertspoon, scoop the squash out of its skin and add to the nuts along with the chestnuts, olive oil, lemon zest, thyme, tamari and a good pinch of salt and pepper. Blitz again to a fine-textured mixture.

Tip the nut roast mixture into an oiled 24cm loose-bottomed tart tin. Use the back of a spoon to press it down into the edges, then make a slight indent in the middle. Let the mixture sit for 10 minutes before roasting for 30-40 minutes, or until crisp at the edges.

Warm about 1 tbsp olive oil in a frying pan over a medium heat, add the sliced red onion and sliced mushrooms and fry, stirring until well cooked.

Whip the silken tofu with the juice of the lemon and half its zest, plus a good pinch of salt and pepper.

Take the nut roast out of the oven and let it sit for 20 minutes to cool a little.

Spoon the soured tofu on top using the back of a spoon to create little ups and downs. Scatter with the onions and mushrooms and finish with finely cut parsley scattered over the top.

Serve in slices with all the trimmings for your festive feast or with a simple salad for a lighter dinner.