Add 1/4 cup of vegetable stock to a sauce pan over medium heat. Add in the flour, cocoa, garlic powder, cumin, chilli powder and onion powder and whisk into a paste. Cook for 2 minutes. Add in the canned tomatoes, tomato paste and remaining vegetable stock and cook until the sauce has thickened to your desired consistency, we like ours to be the consistency of tomato soup . If the canned tomatoes you used weren’t completely smooth you can use an immersion blender to get the sauce smoother.