- Preheat the oven to 180°C/gas 4. Put the oil into a saucepan over a low heat, add the onions and gently cook for 25 minutes, stirring regularly, until they begin to caramelise, turn brown and become soft. If they start to stick, add a teaspoon of water.
- Meanwhile, mix the crushed garlic, chopped parsley, pepper and olive oil together and set aside.
- Slice the baguette into 2cm-thick rings, cutting only about three-quarters of the way through the loaf so that it stays together.
- Stir the onions into the garlic and parsley mixture. Place a spoonful in between each ring of bread, dividing evenly between the slices.
- Fully wrap the bread in foil, and bake for 10-12 minutes. Undo the foil, top with the mozzarella cheese and bake for a further 5 minutes before serving.
- Caramelising the onions will cook them down to about one third of the raw quantity. It's important to cook them really slowly and stir regularly with a wooden spoon.
- Use a wholemeal baguette to boost the fibre content.
- Freezing instructions: Can be frozen ready-to-cook or cooked. Slice, then wrap in foil to freeze. You can then defrost slices as required.