In a small bowl, combine the cumin, garlic powder, chili, salt, lime juice, and olive oil. In a glass baking dish, add the pork loin and pour the spice mixture on top. Cover with plastic wrap and marinate in the refrigerator for at least 1 hour.

Transfer the pork tenderloin to a 4- to 6-quart slow cooker. Cover and cook on LOW for 6 hours.

Remove the pork tenderloin from the slow cooker.

Garnish with lime slices and fresh parsley