Preheat oven to 350 degrees.
Finely chop the stems of the mushrooms and set aside.
Ina large skillet, add garlic and onion and cook for 3-4 minutes until softened. Add quinoa, spinach, diced mushroom stems and Parmesan cheese, Mix well.
Allow to cook for a few minutes until combined.
Add chopped pecans and mix again.
Remove from heat.
Take a full teaspoon of the quinoa-spinach filling and stuff each mushroom.
top with additional Parmesan cheese if desired.
Place on baking sheet and bake in preheated oven for 20 minutes.
Let stand for a few minutes and serve!