Add vinegar, water, sugar, salt, allspice, peppercorns, mustard seeds, and any other optional add-in dried spices to a small pot and bring to a boil. Remove from heat and allow the brine to come to room temperature.
Place your hard-boiled and peeled eggs into a sterilized Mason jar along with cut beets and any fresh options add-ins like garlic or fresh herbs.
Pour the cooled brine over the eggs, seal, and let eggs pickle for at least a day before eating.