Measure and prepare ingredients. Peel and finely dice or chop the onion and garlic, core the chilli and chop finely. Finely grind the cumin and mustard seeds. Heat the oil in a saucepan, add onion cubes and fry lightly, do not brown, add tomato paste and pimentón and let fry briefly. Add the garlic, tomato puree, vinegar, Worcestershire sauce, sugar and spices. Bring to the boil and add the cola, bring to the boil again, turn the stove back to half the heat, add the whiskey and maple syrup and simmer the sauce for around 30 minutes.