In a large bowl combine the chicken with oil and all the spices. Toss the chicken until coated well.
Preheat a 12 inch skillet over high heat.
When the skillet is hot add the chicken and cook for about 6-8 minutes, or until golden and cooked through.
Add the sliced peppers, onion, and lemon juice.
Saute the peppers and onions for about 4 minutes or until they are golden and have softened slightly.
Add in the cooked brown rice, and mix well.
Cook everything for another minute then serve immediately with fresh lime wedges.
Serve fajitas immediately or make it in a big batch and store it in the fridge for up to 4 days.