Mix together the chopped eggs, mayo, mustard, celery salt, and minced dried onion.
You can make the filling 1 day ahead- at this point, you'd need to cover and refrigerate it.
Cut off and discard the root ends of endive, and separate leaves.
Rinse leaves under cool running water, then shake dry.
On the wide end of each leaf, place a generous teaspoon the egg mixture, and then place 1 shrimp atop each.
Sprinkle each filled leaf with paprika.
And now for the artistic portion of the program: for serving: on a large platter, arrange the filled leaves in concentric circles, resembling a flower. If you like, you can place colorful edible flowers in the middle and arrange the leaves around them, for a little color and artistry! You can arrange them on the platter 4 hours ahead, then cover and chill until serving.