2 small fresh red chiles, finely chopped, or 1 teaspoon cayenne pepper
1/2 cup olive oil
2 pounds jumbo shrimp (prawns), peeled and deveined
Salt to taste
Lemon wedges and coarse country bread
To make the sauce, in a jar with a tight-fitting lid, mix the chiles, garlic, salt, olive oil, and vinegar. Cover, shake well, and let rest in the refrigerator for about 1 week before using. You should have about 1 1/2 cups. Shake well before using.
In a mortar, grind simultaneously the garlic and chiles or cayenne pepper to make a paste. Stir in the olive oil. Rub this combination over the shrimp, place them in a bowl, cover, and refrigerate for 4 hours.
Preheat a broiler (or grill pan), or prepare a fire in a grill. Remove the shrimp from the marinade, reserving the marinade. Thread the shrimp onto skewers, piercing the shrimp twice, once near the tall and again near the head. Sprinkle with salt. Broil or grill, turning once and basting with the marinade, until opaque during 5 to 6 minutes total.
Arrange the skewers on a serving platter and garnish with the lemon wedges serve the bread and piri-piri sauce for dipping on the side.