First sauté mushrooms in a splash or two of balsamic vinegar until they're soft. Add small handful of arugula (or spinach) and onion and let wilt.
Get two tortillas and spread garlic on them.
Place tortilla's on baking sheet lined with parchment paper. Then add small spoonfuls of pizza sauce to each covering entire tortilla. Not too thick as you don't want it to fall apart.
Top one of the tortilla's with the mushroom mix, a little more fresh arugula and vegan cheese (if desired). Place other tortilla on top.
Bake for 3 minutes on one side. Flip over (I held it with my hands so it wouldn't fall apart) and bake for 2 min on the other.
Let cool, cut into four squares and top with nutritional yeast and a little more sauce if you'd like.