Serves 4 as a side dish

With a bit of time the humble British onion can be transformed into a star side dish, the oven doing most of the hard work. Delicious served with roasted meat like beef, chicken or duck.

Method

1. Preheat the oven to 180°C
2. Line an ovenproof dish with two crossed sheets of foil big enough to come together to form a parcel 
3. Trim off the papery points of the onions so the flesh is just exposed and cut a cross in the top of each onion about 2cm deep; stand them upright on the foil
4. Drizzle over the olive oil and pour the Guinness around the bottom, sprinkle with salt and place a sprig of thyme on top of each onion
5. Fold the foil around the onions into a parcel and bake for 45 minutes
6. Carefully remove the foil parcel from the dish and transfer the onions back to the dish and pour over the juices; discard the foil. Return to the oven to for 30 minutes so the alcohol can dissipate 
7. Pop a bit of Gruyère cheese into the top of each onion and scatter some over the top; sprinkle with black pepper and cook for a final 15 minutes