Preheat the oven to 200°C unless you’re making the pie in advance. Heat the oil in a large pan. Add the onion and cook gently for 3 minutes, stirring occasionally. Add the garlic, celery and red pepper and fry until just softened. Add the mushrooms and cook for 3 more minutes, stirring until lightly coloured.

Stir the chopped tomatoes, Hendo’s, tomato purée, and oregano into the veg and season with salt and pepper. Bring up to the boil, then reduce the heat and simmer for 5 minutes to get the flavours combined. Add both kinds of beans and cook for 5 minutes, then stir in the parsley.

Transfer the pie filling to an ovenproof dish and set aside. Cook the spuds in a large pot of boiling salted water until tender. Drain, then mash with the butter and milk. Mix in the mustard.

Spread the mash on top of the filling in an even layer, and create texture with the tip of a fork. Sprinkle the grated cheese on top and bake for 30 minutes.

Serve at once with green veg of your choice on the side. Don’t forget the bottle of Hendo’s on the table for everyone to add more!