Preheat your oven to 350 degrees. Chop your potatoes and onion into fairly large pieces. Place in a dish. Add vegetable oil, and 1/2 teaspoon salt, and 1/4 teaspoon black pepper and stir together.
Brown chicken leg quarters by placing skin side down in a skillet over medium heat, brown for about 2 minutes, flip chicken over and brown again for about 2 minutes. Place chicken over potatoes coat with BBQ sauce, bake chicken for about 1 hour. If desired add some additional BBQ sauce before serving.