On a large baking tray, place the tomatoes, peppers, onions and garlic. Drizzle with olive oil and roast in the oven for 40mins until the vegetables are tender and charred.
Pull away the tomato skins and discard. Whizz the vegetable in batches in a food processor until smooth. Pour back into the pan and add the stock, vinegar, worcester sauce and oregano and reheat. Season with salt and pepper.
Heat through and serve immediately with crusty bread.