Wash 2 cups of spinach and dry them. Finely chop half a red onion, crumble 3 ounces of feta cheese, and gather 1 cup of shredded mozzarella.

Gather your tortillas as they will be the base for the quesadillas.

Lay one tortilla flat, layer spinach, crumbled feta, and shredded mozzarella on one half, and sprinkle chopped red onion. Fold the tortilla to enclose the filling.

In a skillet, heat 1 tablespoon of olive oil over medium heat until shimmering. Cook the folded quesadilla for 3 to 5 minutes until golden, then flip and cook the other side for an additional 3 to 5 minutes.

Remove the quesadillas from the skillet, let them rest, then slice into wedges and serve warm.