In a food processor, combine the green bell pepper, onion, garlic, oregano, pepper, lime juice, salt, and parsley. Grind to a coarse paste.
Coat the chicken with the seasoning. Let it rest in the refrigerator for 2 hours.
Preheat the grill to maximum temperature.
While it is heating up, skewer a yellow bell pepper, chicken, and tomatoes alternating. Repeat to make 12 skewers.
Place the skewers on the grill and cook covered for 7 minutes, turn and repeat for another 7 minutes, or until the meat thermometer reads 165ºF (74 ºC) by measuring in the center of a piece of meat. The meat will have some browned spots.
The process is the same whether using a gas, charcoal or stovetop grill.
Remove from the grill, drizzle or brush with olive oil (optional), and serve immediately.
