In a shallow glass dish, mix the oil, lime juice, lime rind, garlic, oregano, red chilli flakes, salt and black pepper. Add chicken, and turn to coat. Cover, and marinate in the refrigerator for 1 hour, turning occasionally.
Preheat barbecue for medium-high heat.
Lightly oil the barbecue hotplate. Drain the breasts and discard marinade. Cook chicken for 6 to 8 minutes on each side, or until juices run clear.
Made this last night-its great as long as you like lime (which I do!) garlic and chilli (ditto!). I used fresh chilli and didn't cook on the barbecue but in a hot, cast iron frypan inside. - 19 Nov 2008