Preheat the oven to 400 F | 200 C. Grease a sheet pan with oil. In a large bowl, add pork, salt and pepper. Toss. Sprinkle cornstarch little by little and mix until well coated.
Transfer pork on the sheet pan. Bake for 10 minutes then open the oven. Carefully add the pineapple and cashew nuts into the pan. Bake for another 10 minutes or until pork is done.
Add cornstarch in a bowl, pour soy sauce in it while stirring. Now stir in ginger and chili paste. Pour on the pork and toss all together. Bake for another 3-4 minutes.