Prepare the pineapple: Cut off the top and bottom of the pineapple, then remove the skin and core. Cut into bite-sized chunks or slices and place in a medium bowl.
Prepare the seasonings: Thinly slice the chadon beni, pimento peppers, hot pepper, and garlic, if using.
Add the sliced seasonings to the pineapple and toss to combine.
Squeeze the fresh lime juice over everything and mix well.
Season with salt and black pepper to taste.
Let the pineapple chow sit for at least 20 minutes before serving to allow the flavors to come together.