Preheat a large skillet or grill pan over medium heat for about 3–5 minutes.

Toss zucchini, red bell pepper, and red onion with olive oil, salt, pepper, and oregano in a mixing bowl. Sauté for 3–4 minutes until slightly softened.

Place one tortilla on the skillet and spread half of the shredded cheese across. Layer with sautéed veggies, sun-dried tomatoes, olives, and feta.

Sprinkle remaining cheese over filling, then place the second tortilla on top to sandwich the fillings.

Cook for 2–3 minutes until golden brown and cheese starts to melt. Press down gently with a spatula.

Flip the quesadilla carefully and cook for another 2–3 minutes until crispy and cheese is melted.

Remove from skillet, let cool, and slice into wedges. Serve warm with dips like tzatziki or hummus.