Mozambique, via Portugal
The piri piri (also peri peri, African bird's eye chilli) arrived in Portugal from Mozambique, Angola, and other Portuguese colonies in Africa — a tiny, intensely hot chilli that became the defining hot condiment of Portuguese cooking and later one of the most globally distributed Portuguese culinary exports through Nando's and similar chains. The traditional technique is a marinade-and-baste method for grilled chicken: the chicken is marinated in a paste of piri piri chilli, garlic, lemon, salt, olive oil, and herbs, then grilled over charcoal and continually basted with the marinade. The heat concentration in the sauce is the variable — from mild to face-numbing, controlled by the quantity of piri piri relative to the other ingredients.
Fresh or dried piri piri peppers are preferable to commercial sauce. The marinade must include garlic and acid (lemon or vinegar) to balance the heat. Apply the marinade at least 2 hours before cooking, preferably overnight. Baste continuously during grilling — each baste adds more flavour and builds a char-crust on the skin. Char is not burning — the caramelised, slightly blackened skin is part of the flavour.
The piri piri chilli grows in Portugal (particularly in Alentejo and Algarve) as a garden plant — dried Portuguese piri piri is available from specialty food shops. The chicken version (frango à piri piri) is most famous, but the technique applies to grilled prawns, lobster, and lamb. Serve with fries and a Portuguese green salad. Pair with ice-cold Sagres or Super Bock.
Using commercial piri piri sauce as the complete dish — it lacks the garlic-lemon depth of the fresh preparation. Not marinating long enough. Basting with the raw marinade after the chicken is nearly cooked — add the marinade only during the first half of cooking to prevent raw-marinade flavour. Under-charring — the black spots are flavour.
My Portugal by George Mendes