1 small head of cabbage, cored and cut into wedges (about 2 1/2 lbs)
1 medium onion, halved and thinly sliced
1/2 teaspoon kosher salt
1/2 teaspoon black pepper
1 cup chicken broth
1 tablespoon brown mustard
1 lb kielbasa, cut into 3-inch pieces
1. Coat the slow cooker crock with cooking spray. Add all the ingredients except the kielbasa to the crock, tossing so that the cabbage is well-coated with the broth and seasonings.
2. Top mixture with kielbasa.
3. Cover and cook on LOW for 7 hours; give mixture a good stir, then cook 1 hour more.