Preheat the oven to 400F. In a resealable plastic bag combine chicken thighs with 1 tablespoon avocado oil, paprika, 1 tablespoon black pepper, 1/2 tablespoon salt, and ancho. Seal bag and massage the chicken pieces with the spices and oil. Set aside briefly to marinate.
Meanwhile, in a large bowl toss the potatoes with the remaining 3 tablespoons avocado oil and remaining salt and black pepper. Ensure potatoes are evenly coated. Spread on a rimmed baking sheet lined with aluminum foil.
Roast for 30 minutes, stirring half way through. Increase the oven temperature to 425F, stir the potatoes once more and bake for another 15 minutes.
While the potatoes cook, heat a grill pan set over medium heat. Thread the chicken pieces onto the wooden skewers, using 4 to 5 pieces per skewer. Coat the chicken evenly with cooking spray.
Place skewers on the grill pan and cover loosely with a sheet of aluminum foil. Grill for 8 minutes, then flip and continue to grill until cooked through, about 10 minutes.