Make the chicken: Season chicken strips on all sides with salt, pepper, and oregano. Set aside.
Add oil to a large skillet and heat over medium high heat. Add your chicken to the skillet in one layer, and cook for about 5 minutes on both sides, or until cooked all the way through.
Assemble the wraps: Spread about 1 tablespoon of ranch dressing on one side of your tortilla. Top with lettuce, onion, and 1 to 2 strips of chicken. Roll into a burrito, and serve!