1. Place eggs in a saucepan, cover with cold water, and bring to a boil. Remove from heat and cover for 10–12 minutes. Transfer to an ice bath and cool completely.

2. Peel the eggs and slice them crosswise (not lengthwise) so each half can stand upright. Scoop out yolks and place them in a bowl.

3. Mash yolks until smooth, then mix in mayonnaise, Dijon mustard, vinegar (or lemon juice), salt, and pepper. Blend until creamy.

4. Stir in parsley or dill. Add green food coloring if using, and mix until evenly tinted.

5. Spoon the mixture into a piping bag with a star tip. Pipe the filling on each egg white in a swirl to resemble a Christmas tree.

6. Decorate with paprika or red pepper flakes for “ornaments.” Add a small star-shaped piece of cheese or carrot on top of each tree.

7. Chill and serve on a platter garnished with greens like parsley or kale.