1 Add garlic and cook a few minutes more. 2  Add tomato puree and spices. 3  Cook 8-10 minutes. 4  Add chicken stock and cook 10 minutes. 5  Add salt and pepper to taste. 6  To thicken sauce; mix 1 Tblsp. cornstarch with a little water to make a paste.7  Add to sauce for the last few minutes. Add garlic and cook a few minutes more. 2  Add tomato puree and spices. 3  Cook 8-10 minutes. 4  Add chicken stock and cook 10 minutes. 5  Add salt and pepper to taste. 6  To thicken sauce; mix 1 Tblsp. cornstarch with a little water to make a paste.