HOW TO DO IT
1. Heat the oven to 200°C/400°F/gas mark 6.
2. Peel and deseed the pumpkin/squash, then cut it into chunks. Place in a pan with salted water to cover and cook over a low heat until the pumpkin is soft and mashable (about 15 minutes). Drain, then mash with a fork. Crush 1 clove of garlic and stir it in, then season with salt and pepper. Set aside to cool.
3. Meanwhile, heat the butter and oil in a frying pan, then add the onion and fry slowly until it’s coloured as brown as you like it. Chop the remaining cloves of garlic and add to the pan with the mushrooms, thyme, sherry and beans. Season well with salt and pepper and let the mixture simmer away until the sherry has reduced – about 10 minutes or so (you don’t want the filling to be too sloppy). At the last moment stir in the spinach leaves to wilt.
4. Place the filling in a casserole dish and spoon the pumpkin mash on top. Mix the cheese with the breadcrumbs and sprinkle on top, then give it a light drizzle of olive oil. Bake in the oven for 35-45 minutes, or until the topping is golden brown.