Boil the eggs. Place eggs in a medium saucepan and cover with cold water by about an inch. Bring to a boil over medium-high heat, then cover, remove from heat, and let sit for 10–12 minutes.
Tip: Transfer the eggs immediately to an ice bath after cooking for easier peeling.
Peel and chop. Gently crack the cooled eggs and peel them. Chop into small pieces, somewhere between chunky and finely diced.
Mix the dressing. In a medium bowl, stir together the mayonnaise, Dijon mustard, and lemon juice until smooth. Season with a little salt and pepper.
Combine. Add the chopped eggs, celery, and fresh herbs to the bowl. Fold everything together until evenly coated.
Taste and adjust. Add more salt, pepper, or lemon juice as desired.
Serve. Spoon onto bread, croissants, or lettuce leaves. Sprinkle lightly with paprika if desired.