1 cup sliced button mushrooms
Cook bacon in medium skillet over medium heat. Drain and crumble. Season chicken with salt and pepper. Layer ingredients in slow cooker in the following order: onions, bacon, carrots, mushrooms, garlic, thyme, pepper, chicken, juice, and broth. Cover and cook on High for 4 hours.
Remove chicken and vegetables to a plate. Ladle 1/2 cup cooking liquid into small bowl; allow to cool slightly. Turn slow cooker to High; cover. Mix reserved liquid, tomato paste and flour until smooth. Return sauce mixture to slow cooker and stir. Add the chicken and veggies back to the sauce being sure that everything gets covered in sauce. Cover and cook for an additional 15 minutes or until thickened.
Serve over mashed potatoes.