If your slow cooker has a stove-top safe insert, place it over medium high heat and add oil to the insert. Sprinkle chicken with salt and pepper and sear on both sides until golden brown, 3-4 minutes a side. (Note: You can also do this in a stock pot.)
Turn off heat and add the next 13 ingredients to the slow cooker (onion through cayenne). Stir well and heat on High for 3-4 hours or Low for 5-6 hours.
Fluff rice with a fork and stir in peas 10 minutes before serving.
Garnish with green olives and fresh parsley to serve.