Remove the phyllo shells from their box and place them on the counter, keeping the shells in their protective tray until ready to use.
In a mixing bowl, beat the cream cheese and Greek yogurt until smooth.
Mix in the pesto until evenly combined.
Then on low speed, add 2/3 of the sundried tomatoes and Parmesan and beat just until blended.
Pipe or dollop the pesto filling into each phyllo shell, then transfer to a serving plate. Top with the remaining sundried tomatoes and chopped parsley or basil. Serve immediately or refrigerate for up to four hours.
Notes
FOR EXTRA CRISP SHELLS: Arrange the shells in a single layer on a baking sheet and bake at 350 degrees for 8 minutes. Set aside to cool.
TO STORE: Assembled Christmas appetizer bites are best eaten within a few hours of assembling. They may be stored in the fridge for up to two days however the phyllo shells will lose their crispness.
MAKEAHEAD: The filling for these Christmas appetizer bites may be made up to two days ahead and stored in an airtight container in the fridge before filling the phyllo cups. Stir the filling before piping if the ingredients have separated.