Prep the Onions: Bring a small pot of water to a boil.

Add the pearl onions and blanch for 1 minute.

Drain and rinse them under cold water.

Trim off the ends and peel off the papery skin.

If necessary, carefully remove extra layers to adjust their size.

Soak the Onions: In a medium bowl, combine the blanched onions with 1 cup of water and 4 teaspoons of salt.

Let them soak for at least 30 minutes to reduce their sharpness.

Drain and set aside.

Prepare the Vinegar Mixture: In a medium saucepan, bring the sherry vinegar to a boil over high heat.

Add the soaked pearl onions and reduce the heat to low.

Simmer for about 2 minutes until they’re crisp-tender.

Infuse with Flavors: Stir in the dried red chili pepper (or crushed red pepper), whole peppercorns, bay leaf, cloves, and dried thyme.

Remove the saucepan from the heat and let the onions steep in the vinegar mixture for an additional 30 minutes.

Serve or Store: Remove the bay leaf and let the onions cool to room temperature.

Serve these deliciously flavored sherry vinegar pearl onions as a side dish or as part of a tapas spread.

For longer storage, store them in a covered container in the refrigerator for up to 3 weeks.