In a large skillet, heat the olive oil over medium heat. Add the red onion and sauté for 2-3 minutes until softened.
Add the sliced mushrooms and minced garlic. Cook for an additional 5-7 minutes until the mushrooms have released their moisture and are golden brown.
Stir in the chopped spinach and cumin. Cook until the spinach is wilted, about 2 minutes. Season with salt and pepper to taste. Remove from heat and set aside.
In a separate skillet over medium heat, place one tortilla and sprinkle half of the mozzarella cheese on one half of the tortilla.
Spoon a generous amount of the spinach and mushroom mixture over the cheese, followed by crumbled feta on top. Sprinkle the remaining mozzarella over the filling.
Fold the tortilla in half and cook for about 3-4 minutes until the cheese begins to melt and the bottom side is golden brown. Carefully flip and cook for another 3-4 minutes until the second side is golden.
Remove from the skillet and let cool for a minute before slicing into wedges. Repeat the process for the remaining tortillas and filling.
Notes
Serve on a colorful plate, garnished with fresh cilantro and accompanied by salsa or guacamole.