How to Make It
Bring 4 cups water, sugar, salt, peppercorns, bay leaf, beet, and vinegar to a simmer in a medium pot. Cover, reduce heat to medium, and simmer for 20 minutes. Remove from heat; let cool for 45 minutes.
Meanwhile, bring a medium pot of water to a simmer. Carefully lower eggs into water and simmer for 8 minutes. Transfer to an ice bath to cool; peel and leave whole.
Transfer eggs to a clean quart-size jar. Discard beet and pour cooking liquid over eggs to cover. Cover and refrigerate for at least 2 hours and up to overnight, turning jar occasionally to make sure eggs pickle evenly.
Serve eggs halved or whole, at room temperature, with flaky salt.