Step 1In a spice grinder or food processor, combine the onion, garlic, caraway and salt, and pulse a few times to coarsely break up. Move the spice blend to a bowl and stir in the fennel, poppy, celery and sesame seeds. This makes a scant ¼ cup spice blend. Store, tightly covered, in a cool, dry place.
Step 1In the bowl of a food processor, pulse together the egg yolks, mustard, mayonnaise, vinegar, chives, chervil and white vinegar. Season with ½ teaspoon salt, or to taste. This makes about 1 ½ cups yolk mixture. Press the mixture through a fine mesh sieve, then place in a piping bag.
Step 2Pipe the filling into the egg whites, dust with Everything spice and a little paprika, then finish with a drizzle of olive oil before serving.