1. Start by combining the diced tomato, red onion, chopped spinach, feta cheese, and mozzarella cheese in a mixing bowl. Gently toss the ingredients together, ensuring the flavors are evenly distributed. Finish by seasoning the filling with a sprinkle of black pepper to taste.

2. Lay each burrito-style tortilla flat on a clean work surface. Scoop one-third of the prepared Mediterranean filling onto one half of each tortilla, leaving the other half empty. Fold the empty half over the filled half, creating a classic quesadilla shape.

3. Heat a small amount of oil in a large skillet or on a griddle over medium heat. Carefully place the folded quesadillas in the hot pan, working in batches if necessary. Cook for 3 to 4 minutes per side, pressing gently with a spatula, until the tortillas are golden brown and the cheese is melted and bubbly.

4. Once the quesadillas are perfectly cooked, remove them from the heat and slice them into triangles. Serve the Mediterranean Quesadillas warm, accompanied by your favorite dips, salsas, or fresh herbs for an extra burst of flavor.