Carefully slice eggs in half, lengthwise. Scoop out the yolks into a small mixing bowl. Mash yolks with a fork, then add enough mayo to moisten and combine. Add dash of vinegar and the mustard, combine well. Add diced onion, chipotle powder, and curry, mixing until smooth and creamy. (Add a bit more mayo if the mixture seems too stiff.) Taste for seasoning and add salt and pepper to taste. Spoon the filling carefully into egg halves and place on a serving platter. Sprinkle eggs with paprika, and garnish with chives or cilantro if desired.