In a small bowl, whisk together the orange juice, soy sauce, rice vinegar, brown sugar, ground ginger, onion powder, and garlic powder to make a marinade. Place the pork chops in a large resealable bag and add the marinade to coat. Seal the bag and place in the refrigerator for at least 2 hours, up to overnight. Transfer the pork chops to a shallow dish. Pour the marinade into a small saucepan. In a small bowl, dissolve the cornstarch into 2 teaspoons of cold water to make a slurry. Place the saucepan of marinade over medium heat and bring to a boil. Reduce the heat to low and whisk in the slurry. Cook, whisking, until the sauce thickens, about 2 minutes. Remove from the heat and set aside to use as a base for the grilled pork chops and pineapple. Preheat an indoor grill, grill pan, or outdoor grill to medium-high heat. Place the pork chops on the grill and cook, brushing often with the base as you grill. Add the pineapple slices to the grill and cook for 1 to 2 minutes on both sides. Let the pork chops rest for 2 to 4 minutes before serving. To serve, place one grilled pineapple slice on top of each pork chop and serve with any remaining marinade sauce.
Tip – You can use your oven as well.