Heat coconut oil in a large skillet.
Add red onions to skillet and cook until translucent. Then add spinach, and cook just one more minute until spinach starts to wilt. Transfer vegetables to a plate.
Spread the goat cheese onto all 4 corn tortillas, distributing evenly.
In same skillet (do not clean skillet from vegetables), place 2 of the tortillas, goat cheese-side face up, and then spread vegetable mixture on top of each. Next, place other 2 tortillas, goat cheese-side down, on top of the other tortillas to make 2 "sandwiches."
Cover skillet and cook for 2 minutes on medium heat. Flip each quesadilla over carefully, and cover again and cook 2 more minutes.
Serve immediately with a side of "secret's in the spirulina" guacamole.