Trim excess fat from chops. Sprinkle with salt and pepper.
In a 12-inch nonstick skillet, heat oil over medium-high heat. Add pork chops. Cook 8 to 10 minutes or until an instant-read thermometer inserted through the side into the centers registers 145°F, turning once halfway through cooking. Remove from skillet. Cover with foil.
Add sweet potatoes and onion to the skillet with 1 tablespoon of the butter. Sprinkle with additional salt and ground black pepper. Cook over medium heat, stirring occasionally, 8 to 10 minutes or until sweet potatoes are tender and onions are caramelized.
To skillet, add garlic, remaining 1 tablespoon butter, brown sugar and sage; cook, stirring frequently, 2 minutes more. Return pork chops to skillet just to heat through.