01 - Cube the chicken breast and dice the onion. Mince the garlic and cut the biscuit dough or pie crust into bite-size pieces.
02 - Layer the chicken in the base of the slow cooker. Evenly distribute the onion, garlic, frozen vegetables, dried thyme, parsley, salt, and pepper.
03 - In a mixing bowl, whisk together the chicken broth, milk, and flour until smooth. Pour the mixture over the ingredients in the slow cooker.
04 - Cover and cook on low heat for 6 hours or high heat for 3 hours, until the chicken is cooked through and the sauce has thickened.
05 - Arrange pieces of biscuit dough or pie crust evenly over the filling inside the slow cooker.
06 - Cover and cook on high for an additional 30 to 45 minutes, or until the topping is golden and cooked through.
07 - Allow to cool for 5 minutes before spooning portions into bowls and serving warm.