Place chicken thighs, pesto, ranch dressing (dry from the packet) and broth into crock pot. Stir gently to coat chicken and combine everything.
Place lid on top. Cooking tip: It tends to cook in half the time you set on the crock pot, i.e., a 6-hour high setting means the chicken should be done in about 3 hours, depending on how many thighs are in there and how thawed they were to start. Leave thighs whole or chopped. (If you chop, add them into the pot again on warm for 15 minutes so they can soak up more flavor! It's also a great way to make sure they are cooked through--just chop the meat and cook on high a while more.)
These thighs are great with veggies, or in a salad, or cold out of the fridge. They also freeze wonderfully.