2 ripe pineapples
1/2 large Spanish onion, thinly sliced
1 tablespoon smashed fresh oregano leaves
1 teaspoon black peppercorns
20 garlic cloves, crushed
6 habanero peppers or chile peppers of choice, stems removed, peppers coarsely chopped
1 tablespoon cider vinegar, or as needed
1/2 teaspoon salt, or as needed