Put 4 of the yolks into a medium sized bowl; discard the remaining yolks.
Submerge the egg white halves in cold water to remove any remaining specks of yolk; drain on paper towels.
Meanwhile, add the goat cheese to the bowl of yolks, and, with a fork mash the two together.
Add the yogurt and mix until smooth.
Add the chives, lemon zest, pepper and salt and mix to combine.
Transfer the mixture to a piping bag fitted with a small star tip.
Pipe the filling into the 20 cavities, garnish with micro arugula and serve.
Notes
I buy my eggs hard boiled. You can find them in pretty much every supermarket. They are priced reasonably, and buying them pre-done cuts the prep time significantly.