While quinoa cooks, shred cheeses (if not already bought that way). Thaw the spinach.
Chop and squeeze artichoke hearts in a paper towel or kitchen towel until thoroughly dry. Do the same for the spinach.
Preheat your oven to 350 degrees F and spray a mini muffin tin with cooking spray.
Add all of the ingredients to a bowl and mix until thoroughly combined.
Divide the mixture evenly between the cups of the mini muffin tin, and press down to pack it in firmly.
Bake for 20-25 minutes, or until golden brown and crispy. Let cool for a couple minutes before loosening from the pan with the tip of a butter knife. Remove from pan and serve.