In a large skillet over medium heat, add a tablespoon of olive oil and sauté thinly sliced red onion and diced bell peppers for about 3–4 minutes until they soften and become fragrant. Stir in the fresh spinach and cook just until wilted, which should take another 1–2 minutes. Remove the skillet from the heat and set the vegetable mixture aside to cool slightly while you assemble your quesadillas.

Take a flour tortilla and sprinkle a generous layer of shredded mozzarella cheese on one half. Add a portion of the sautéed vegetable mixture on top, followed by crumbled feta cheese and a pinch of dried oregano for that Mediterranean flair. Fold the tortilla in half, gently pressing down to secure the filling inside. Repeat with the remaining tortillas to create additional Cheesy Mediterranean Quesadillas.

In the same skillet, heat a drizzle of olive oil over medium heat. Carefully place your folded quesadilla in the skillet and cook for 2–3 minutes until the bottom is golden brown and crispy. Using a large spatula, flip the quesadilla over and cook for another 2–3 minutes on the other side until the cheese is melted and the exterior is beautifully golden.

Once cooked, transfer your Cheesy Mediterranean Quesadilla to a cutting board and let it rest for about a minute. With a sharp knife or pizza cutter, slice it into wedges for easy serving. Arrange the slices on a platter, and consider pairing them with a side of homemade salsa or a fresh salad for a delightful and complete meal.