Heat a tablespoon of olive oil in a skillet over medium heat. Once shimmering, add the chopped spinach and cook for about 2 minutes, stirring until wilted and tender.
2 large flour tortillas
Remove the cooked spinach from the skillet and set aside briefly to cool slightly. Wipe out the skillet if needed.
Lay a tortilla flat on a clean surface and sprinkle half of the crumbled feta evenly over one half of the tortilla.
2 large flour tortillas
Spread the cooked spinach evenly over the feta, then fold the tortilla in half to enclose the filling.
2 large flour tortillas
Place the filled tortilla in the preheated skillet over medium heat. Cook for about 3–4 minutes, until the bottom is golden and crispy.
Carefully flip the quesadilla using a spatula and cook for another 3–4 minutes on the other side until golden brown and the cheese is melted.
Transfer the cooked quesadilla to a cutting board and let it rest for a minute. Then, slice into wedges to reveal the gooey cheese and wilted spinach inside.
Repeat the process with the remaining tortilla, feta, and spinach. Serve the quesadillas warm, ideally with a side of fresh salad or salsa if desired.
