Cut the whole chicken into 8 pieces if not already cut: separate breasts, thighs, drumsticks, and wings.
In a small bowl, mix together kosher salt, black pepper, garlic powder, onion powder, smoked paprika, dried thyme, and dried rosemary.
Rub the spice mixture evenly over all the chicken pieces.
Heat olive oil in a large skillet over medium-high heat. Add chicken pieces skin side down and sear for 3-4 minutes until golden brown. Flip and sear the other side for 2-3 minutes. Work in batches if necessary. Remove chicken and set aside.
Place sliced onion and minced garlic in the bottom of the slow cooker.
Arrange the seared chicken pieces on top of the onions and garlic in the slow cooker.
Pour 1 cup of low sodium chicken broth around the chicken pieces.
Cover and cook on low for 6 hours, or until the chicken is cooked through and tender (internal temperature of 165°F).
Once cooked, carefully remove chicken pieces from the slow cooker and serve with the cooked onions and pan juices.