1 dozen eggs, hard boiled and peeled
2 cups vinegar (cider or white)
2 Tbsps Dijon mustard
1 Tbsp salt
2 tsp turmeric
2 tsp sugar
Put the hard boiled eggs in a jar with the sauce. Age for one to two weeks.
Notes for making big batches: put 2 dozen raw eggs (not too fresh) in a spaghetti pot. Cover with cold water. Bring to a boil, then turn heat to low and let sit for 15 minutes. Immediately bash the bottoms while holding under a stream of cold running water, and put them in a sinkful of cold water, one by one. Crack all over before peeling, and start at the wide bottom. Takes an hour or so to boil and peel 2 dozen. 3 dozen fit in a one-gallon glass pickle jar. Put plastic wrap over the mouth of the jar before putting the lid on, to prevent the lid-metal from corroding against the vinegar.
Let sit for a week or week and a half. Stir occasionally to distribute the color. Eggs will be bright yellow.