Place onions, red, green, yellow peppers and tomatoes into a roasting dish. Add the Schwartz for Chef Garlic Puree and the olive oil and combine all ingredients. Place in a hot oven and roast for around 45 mins.
Remove from oven and transfer ingredients into a pan. Add the stock and Schwartz for Chef Italian seasoning. Bring back to the boil and simmer for 30 mins. Season and serve.