Dice the pineapple into bite-sized cubes. Dice the jalapeños and juice the limes.
Next, heat the vinegar and water in a small sauce pan. Bring it to a simmer. Pour the mixture into a large mason jar, and stir in the salt and lime juice. Next, add the diced pineapple.
Last, add the diced jalapeños and cilantro. The contents of the jar should be fully submerged in the liquid. Top off with a little more hot water, if needed.
Cover and set it aside on the counter for about an hour. If you're making it in advance, set the jar in the refrigerator overnight.
Video
Notes
To store: Store the pickled pineapple in any airtight glass container in the refrigerator for up to a week.