Heat a pan and add a little oil.
Sauté chopped mushrooms until they release moisture and turn golden.
Add garlic and cook for a few seconds.
Add fresh spinach and cook until wilted.
Season with salt, black pepper, and optional chili flakes.
Place a tortilla on a pan, spread the mushroom-spinach mixture evenly.
Add cheese if desired and cover with another tortilla.
Cook on both sides until crispy and golden brown.
Cut into wedges and serve hot with salsa or dip.