Base: Place the cubed potatoes at the bottom of the slow cooker. Drizzle with oil, salt, and pepper. Chicken: Layer the thin-sliced chicken breasts on top of the potatoes.
Sauce: Pour the entire bottle of BBQ sauce over the chicken and potatoes.
Cook: Cover and cook on Low for 3-4 hours (check at 3 hours since thin chicken cooks fast!).
Serve & Store: Serve the potatoes and half the chicken. Shred the remaining chicken and store it in an airtight container for Monday.