In a skillet set over medium-high heat, cook bacon until starting to brown and fat is rendered. Using a slotted spoon, transfer bacon to a slow cooker, leaving rendered fat behind. In the same pan, brown turkey breast on both sides and transfer to slow cooker. In the same pan again, add onions and garlic and sauté until fragrant. Deglaze pan with a splash of chicken stock and transfer to slow cooker along with paprika, cumin, tomato paste, BBQ sauce, bay leaf, Worcestershire sauce, apple cider vinegar and remaining chicken stock.