For the pastry, put the flours and butter in a food processor. Blitz until the mixture resembles fine breadcrumbs (you can also rub them together using your fingers). Tip in the caraway seeds and pulse to combine. Add the egg yolk or plant milk and pulse again until you have a soft dough. If needed, add more plant milk or water, 1/2 tsp at a time, just to bring the dough together. Chill for 20 mins.

Tip the mushrooms into a large frying pan. Cook over a medium heat until the liquid has been released and evaporated, about 15 mins. Drizzle in the oil, then add the onions and peppers. Fry for 8-10 mins until the mushrooms are golden and the veg has softened.

Stir in the garlic and chillies and cook for 1-2 mins until fragrant. Add the spices, stir and cook for 1 min before adding the tomatoes and half a can of water. Stir, then cook for 5-10 mins until thickened slightly, adding a little water if needed to loosen. Add the spinach and cook for a few minutes to wilt.

Heat the oven to 200C/180C fan/gas 6. Tip the mixture into a pie dish. Roll the pastry out on a lightly floured surface until 1/2cm thick and large enough to cover the dish. Lay it on top and crimp the edges to seal. Poke a couple of holes in the top for steam to escape, then brush with some egg yolk or plant milk. Bake for 30-35 mins until golden.