Cut your courgettes, red onions, peppers, and aubergines into chunks of roughly 2cm. Add to a large baking tray, with the 2 cloves of sliced garlic, a teaspoon of dried oregano and some seasoning, and toss in the olive oil to evenly coat all the vegetables.
Place the baking tray in the oven and roast for 30 minutes, turning the vegetables over halfway through cooking.
If using fresh tomatoes, skin them by placing them in a heatproof bowl, covering them in boiling water for 90 seconds. Remove the tomatoes from the water, make a slice in the skin and peel it off. The riper the tomatoes, the easier this is.
Remove your tray of vegetables from the oven and add your tinned tomatoes or freshly skinned tomatoes, along with 200ml water (swirled in the can if using a tin of tomatoes), the chopped fresh herbs, bay leaf, and season again.
Reduce the oven to 160 °C and place the tray back in the oven for another 30 minutes.