The mysterious McDonald's Szechuan Sauce has evaded customers time and time again. Sadly for fans, there's a reason the dipping sauce is not a regular offering.

Add the garlic, chilli, Szechuan peppercorns and five-spice powder and cook for 1 minute. Add the marinated beef (reserving the marinade) and stir-fry for 2-3 minutes. Remove and keep warm.