Piri piri sauce is a marinade or sauce made from the small, spicy piri piri chile as well as citrus, onion, pepper and herbs. It originated in Portugal and is common in many southern African cuisines. Piri piri is a complex sauce, with sweet, sour and salty notes as well as heat, and a roundness that comes from the onions and peppers in it. It's particularly popular with chicken. Awareness is still low among consumers, but its appearance on menus has grown 41 percent over the past four years.