Place eggs in stock pot and cover with water. Add vinegar and bring to a boil over high heat. Turn off the heat and cover. Let sit for 15-18 minutes. Drain water. When cool enough to touch, remove shells.

Slice each egg in half, lengthwise. Remove yolks and place in a food processor. Add mayo, mustard, lemon juice and salt to the yolks. Blend until smooth. Scoop the yolk mixture into a plastic baggy. Use scissors to snip off the end of the baggy. Use the baggy like a pastry bag to pipe the yolk mixture into the egg whites. Spoon a small amount of caviar on each egg.

Variation: Instead of caviar, garnish each egg with a small piece of smoked salmon and sprinkle with chives.