Preheat the oven to 150°C fan/170°C/315°F/gas mark 2½.
In a baking dish (sized approx. 30 x 24cm/12 x 9½ inches), add the tomatoes, chickpeas, garlic, tomato purée, oregano, thyme, chilli flakes, and season with salt and pepper. Pour over the olive oil and give the dish a good shuffle so that everything is well combined. Roast in the oven for 45 minutes or until the smaller tomatoes have collapsed and the larger ones are starting to char. Stir halfway through.
Remove from the oven and turn up the oven to 180°C fan/200°C/400°F/ gas mark 6. Mash the garlic cloves into the oil and give the ingredients a stir. Season both sides of the fish with salt and pepper, make two wells in the tomatoes, and nestle in both pieces of fish. Scoop up a little of the oil from the baking dish and drizzle over the fish. Put the dish back into the oven and bake for 8–10 minutes, or until the fish is no longer opaque and is cooked through. A thicker fillet may take longer.
When ready, sprinkle over the chopped herbs and squeeze the lemon wedges over the fish. Taste the saucy tomatoes and adjust the seasoning if needed. Serve straight to the table.
