Cut the bottom off the mushroom stems, then pop the stems off of the mushroom caps.
Chop the stems into small chunks.
Make the filling. Combine the stems, artichoke hearts, sundried tomatoes, pine nuts, greens, pesto (or Italian seasoning), red pepper flakes and cream cheese in a bowl.
Stuff each mushroom cap with filling.
Gently put the mushroom caps on a baking sheet lined with parchment paper.
Bake at 350 degrees for 15-20 minutes. Take out of the oven and let cool slightly.
The bottoms of the mushrooms will be wet. Lightly dab off the moisture with a clean towel.
Serve warm.