Pre-heat the oven 200°C/180°C fan forced/Gas mark 5

Cut the zucchini and capsicum into large dice.

Place the veg in a single layer on a large roasting tin (or two smaller ones)

Pour over the oil, sprinkle over the dried herbs, season generously with salt and pepper and use your hands to mix until everything is well coated.

Roast for 20 minutes.

Cut the onion into thick wedges and add to the roasting tin, stir gently and roast for a further 15 minutes.

Remove the garlic from the roasting tin and set aside.

Add the tinned tomatoes and balsamic vinegar and return to the oven for 15-20 minutes.

Remove from the oven and tip everything carefully into a food processor/blender.

Squeeze the flesh from the garlic cloves and add to the food processor/blender.

Purée until smooth.

Check the seasoning and use within 3 days. Alternatively freeze for up to 6 months.