Baked stuffed onions with rich mushroom ragù

Method

1. Bring a large saucepan of lightly salted water to the boil. Top and tail the onions, being careful not to take too much away from the root end so they stay in 1 piece. Add to the water with 1 parsley sprig, 2 rosemary sprigs and 1 unpeeled garlic clove. Cook for 12-15 minutes, until just tender. Drain well, discarding the herbs and garlic, and cool slightly. Push out the onion centres with your fingers. Set aside the thick onion cases in a buttered ovenproof dish to stuff later. Finely chop half the onion centres for the ragù (use up the remainder in another dish).
2. Meanwhile, put the mushrooms in a bowl with 500ml boiling water. Set aside for 20 minutes to soften. Strain through a fine sieve and set aside, reserving the liquid.
3. Make the ragù. Heat the oil in a saucepan over a medium heat. Add the chopped onion and cook for 5 minutes, until softened. Add the mushrooms, 1 rosemary sprig and the remaining whole garlic clove. Cook for 1 minute, then add the Marsala. Bubble until reduced and syrupy, then stir in the tomato purée and cook for 1 minute. Add the mushroom liquid, discarding all but the last tablespoon – this may be gritty. Bring to the boil, reduce the heat, cover, and simmer for 30 minutes, until reduced and thickened slightly (the mix should still be fairly loose). Discard the rosemary sprig and garlic clove, season and set aside.
4. Preheat the oven to 200°C/fan180°C/gas 6. Make the stuffing. In a large bowl, mix the breadcrumbs, most of the Parmesan, a handful of chopped parsley (save some leaves to garnish) and the picked, chopped leaves of the remaining rosemary sprig. Stir in 3-4 tablespoons of the liquid from the ragù to bind and season with plenty of pepper. Fill each onion case with stuffing.
5. Spoon the mushroom ragù over the onions, cover with foil and bake for 40-45 minutes. Uncover, sprinkle with the remaining Parmesan and bake for a further 15 minutes, until tender and pale golden.
6. Divide the stuffed onions and mushroom ragù between warmed plates. Garnish with chopped parsley to serve.