Add the dried shrimp to a pan on medium high heat with no oil and cook until no more moisture remains. A cast iron pan works best if you have one, but a nonstick pan will work as well.
Add pineapple to shrimp and stir often, letting the pineapple caramelize, 2-3 minutes
Turn off the heat and add the scallions. Stir through to wilt.
Salt and pepper the dish to taste. The shrimp should already be salty enough on its own.