Peel the red onions but leave them in one piece because the onion might fall apart while boiling. You need them to stay in one piece for roasting later on. Then place onions in a large saucepan and add the bay leaf, garlic cloves, water, balsamic vinegar and red wine or port wine. Season with some pepper and salt.

Place the pan over high heat until the onions are boiling. Then turn the heat low. Let them simmer for about 25 minutes. Then remove the cooked onions from the pan. Let them cool down.

Chop off both ends, the roots and stems. Then slice the onions in half lengthwise.

Sprinkle a baking tray with some olive oil and season with a pinch of salt and pepper. Place the onions on it, largest side up. Sprinkle with extra olive oil, pepper and salt.

Roast the red onions under a hot grill for a couple of minutes until nicely browned on top. Because all grills are different, cooking time can differ. Mine took 18 minutes to get the best result. Keep an eye on the onions. They can burn fast. Once the onions are done, remove them from the grill. Place them on a serving plate. Sprinkle with extra olive oil and the fresh thyme leaves. Serve hot to lukewarm.