TheKitchn w/small adjustments. A small test batch was prepared using three eggs. *I placed the hard boiled eggs into a Mason jar first then poured all the liquid from a 14-16 ounce can of diced beets into the jar followed by the apple cider and only added enough to completely cover the eggs.
Hard boil your eggs and remove the shells. Set the eggs aside to cool.
BRINE: Pour the juice from a can of beets into a large mason jar or non-reactive bowl. Add cider vinegar, sugar, peppercorns, and salt-enough to cover. Carefully (that beet juice will stain!) lower the peeled eggs into the brine. Cover and refrigerate for at least 12 hours, or up to 3 days. The longer you leave them in the brine, the more sour and pink they'll end up. I brined the eggs for 24 hours.
FILLING: When brining time is finished, cut each egg in half and scoop out yolks. Place yolks in a medium-sized bowl, along with the Dijon mustard, mayonnaise, curry powder and olive oil. Mix and mash until smooth. Add a little bit of milk or cream to the mixture for extra creaminess. Salt and pepper to taste.
Using a pastry bag or a plastic bag with the corner cut off, pipe the yolk mixture back into the pink egg cavities. Garnish with chopped herb and season with salt and pepper.