1: To make the tzatziki sauce, combine Greek yogurt, cucumber, garlic, dill, lemon juice, lemon zest, and mint in a small bowl; season with salt and pepper to taste. Drizzle with olive oil and refrigerate for at least 10 minutes.
2: Preheat oven to 400 degrees F and line a baking sheet with parchment paper.
3: Top each tortilla with spinach, sun dried tomatoes, olives, and cheeses, then top with another tortilla.
4: Repeat with remaining tortillas to make 4 quesadillas.
5: Place quesadillas onto the prepared baking sheet and bake until the cheese has melted, about 8-10 minutes.
6: Serve immediately with tzatziki sauce, garnished with dill if desired.
