Heat the oil in a large saucepan on medium heat. Add the onion, celery and peppers, and soften with a small pinch of salt, stirring often, for about 5 minutes.
Add the garlic, red peppers, creole seasoning, and cayenne pepper and cook for about 30 seconds, stirring regularly, until the aroma is released.
Add the tomatoes, stock, vinegar, Worcestershire sauce, tomato purée, and butter.
Bring the sauce to the boil, then simmer, with the lid slightly off, for 15 minutes, stirring occasionally until reduced and thickened. Season to taste.