Preheat your oven to 375 degrees. Spray the inside of a 12 cup muffin tin with cooking spray. Set aside.
In a blender or food processor, combine the Greek yogurt and roasted red peppers. Puree until smooth.
In a large mixing bowl, combine the cooked elbow macaroni, the chicken, artichoke hearts, kalamata olives, and the yogurt/red pepper puree. Mix well.
In small bowl, combine the panko bread crumbs and olive oil. Mix well.
To assemble the mac 'n cheese muffins, scoop the macaroni/chicken mixture evenly into each greased cup of the muffin pan. Top each one evenly with the panko bread crumbs mixture and the crumbled Feta cheese.
Bake for 15-20 minutes, or until heated through. Let the muffins stand for 10-15 minutes before removing them from the pan.