Season the pork chops lightly with salt and pepper and place them in an even layer at the bottom of a 6-quart slow cooker.
In a small bowl, whisk together the teriyaki sauce, brown sugar, minced garlic, grated ginger, and 1/4 cup of the reserved pineapple juice.
Pour the sauce mixture over the pork chops, ensuring they are well coated.
Arrange a pineapple slice on top of each pork chop.
Cover and cook on the LOW setting for 5 to 6 hours (or HIGH for 2.5 to 3 hours) until the pork is tender and cooked through.
Optional: To thicken the sauce, remove the chops and pineapple. Whisk the cornstarch slurry into the liquid in the pot and cook on HIGH for 10 minutes until glossy.
Serve the chops topped with the pineapple rings and a generous spoonful of the thickened teriyaki glaze.
Garnish with fresh parsley or cilantro.