Add vinegar, water, sugar, salt, garlic, and bay leaf to a medium saucepan set over high heat. Stir together and bring to a simmer. Cook for 10 minutes or until the sugar and salt has completely dissolved.
Remove the saucepan from the heat and let cool. The brine can be placed in the refrigerator to cool faster.
Crack and peel your hard boiled eggs and discard the shells.
Add the peeled eggs to a quart jar intermingled with the raw onion slices.
Pour the cooled brine into the jar, ensure the garlic cloves and bay leaf make it into the jar.
Cover jar with the lid and seal it shut, then place it in the refrigerator for at least one week prior to enjoying.
Notes
Approximately 12 large eggs will fit in a quart jar. You should have enough pickling liquid leftover to make 24 pickled eggs if you wish.