Brush a stove-top grill pan or griddle with olive oil and preheat to medium-high. Season both sides of the chicken with the salt and black pepper. Add the chicken to the hot pan and cook for 5 –7 minutes per side, until cooked through. Remove the chicken from the pan and, when cool enough to handle, shred the chicken with two forks.
Transfer the shredded chicken to a medium saucepan and add the salsa. Set the pan over medium heat and bring to a simmer. Simmer for 2 minutes to heat through. Remove the pan from the heat and set aside.
Wrap four of the tortillas in a paper towel and microwave on high for 20 seconds to soften. Arrange the tortillas on a flat surface and spoon the chicken mixture onto each tortilla. Roll the tortillas up tightly and secure with wooden picks. Arrange the tortillas side by side on a large baking sheet and brush the surface with the olive oil. Repeat with the remaining tortillas and chicken, working in batches of four to prevent the tortillas from drying out.
Transfer the baking sheet to the oven and bake for 25–30 minutes, until the tortillas are golden brown and crisp.