In a small bowl, combine parsley, garlic, salt, pepper, onion powder and paprika. Rub over the front and back of the chicken thighs.
Heat oil in a large pan over medium heat.
In two batches, brown chicken, skin side down, in hot pan. This will take 2-4 minutes.
Pour chicken broth in the bottom of a 2.5-4 quart slow cooker and add chicken thighs, skin side up, trying not to overlap chicken if possible. (If you have to, that is fine, they may just take a little longer to cook through)
Put the lid on and cook on low for 5-6 hours or high for 3 hours, until a meat thermometer reads 165 degrees F in the thickest part.