Preheat the oven to 200°C, 180°C fan or Gas Mark 6.

Cut the tomatoes into halves or quarters, depending on their size. Remove the stalks and seeds from the peppers, then cut them into large pieces.

Peel the onion and cut it into wedges. There is no need to chop the vegetables finely, as everything will be blended after roasting.

Place the tomatoes, peppers and onion in a large roasting tray. Add the garlic cloves, keeping their skins on to prevent the garlic from burning.

Drizzle everything with the olive oil.

Toss the vegetables until lightly coated, then arrange them in a single layer.

Roast for around 40–45 minutes, turning the vegetables halfway through, until they are soft and beginning to brown around the edges.

Remove the tray from the oven and allow the vegetables to cool for a few minutes.

Carefully squeeze the roasted garlic from its skin. Transfer the garlic and all the roasted vegetables, including any juices from the tray, to a blender.

Add around three-quarters of the vegetable stock and blend until smooth. Add more stock gradually until the soup reaches your preferred consistency.

Alternatively, place everything in a large saucepan and blend with a stick blender.

Pour the soup into a saucepan and gently heat it for around five minutes.

Taste and adjust the seasoning.

Serve hot with fresh herbs, croutons or a swirl of cream.