Add the pineapple chunks and sliced jalapeños into a clean mason jar or airtight container.
In a small saucepan, combine the white vinegar, water, sugar (or honey), salt, garlic cloves, black peppercorns, and chili flakes.
Bring the mixture to a gentle simmer over medium heat, stirring until the sugar and salt dissolve completely.
Carefully pour the hot brine over the pineapple and jalapeños until fully covered.
Let the jar cool to room temperature.
Seal tightly and refrigerate for at least 12–24 hours before serving for the best flavor.
