Place eggs in a saucepan and cover with cold water. Bring to a boil, cover, and remove from heat. Let sit for 10–12 minutes. Transfer to an ice bath and cool completely.
Prepare the Eggs
Peel eggs and slice in half lengthwise. Remove yolks and place them in a mixing bowl. Arrange whites on a serving platter.
Make the Filling
Mash egg yolks until smooth. Add mayonnaise, mustard, vinegar (or lemon juice), salt, and pepper. Mix until creamy and well combined.
Fill the Egg Whites
Spoon or pipe the yolk mixture evenly into the egg whites.
Garnish & Serve
Sprinkle with paprika or herbs if desired. Chill for 15–30 minutes before serving for best texture.