Begin by finely chopping a handful of fresh spinach and a small red onion. In a mixing bowl, combine the chopped spinach with crumbled feta and shredded mozzarella cheese.

Lay one tortilla flat on a clean surface. Spread the spinach and cheese mixture evenly across the tortilla, leaving a small border. Top with another tortilla.

In a large skillet, heat 1-2 tablespoons of olive oil over medium heat. Once warm, place the assembled quesadilla in the skillet.

Cook for approximately 3-4 minutes, or until golden brown. Gently flip and cook for an additional 3-4 minutes.

Remove from skillet, allow to cool for a minute, then slice into wedges. Garnish optionally with fresh parsley or tzatziki.