Heat the olive oil in a medium skillet over medium heat. Add chopped bacon; cook and stir for 3 minutes. Add shallots and onions; sauté for 6 minutes. Add mushrooms and garlic; sauté for 3 minutes.
Transfer mixture to a slow cooker.
To the same skillet, add the chicken; cook for 5 minutes per side. Add to the slow cooker and stir to combine ingredients. Cover and cook on LOW for 6 hours or until chicken is tender and cooked through.