01 - Set up three bowls: one with flour mixed with smoked paprika, garlic powder, and salt; another with whisked eggs; and a third with panko breadcrumbs. Separate onion slices into individual rings.
02 - Dredge each onion ring in flour mixture, dip into beaten eggs, then coat thoroughly with breadcrumbs. Heat vegetable oil in a deep skillet over medium-high heat. Fry onion rings in batches for 2-3 minutes until golden brown and crispy. Drain on paper towels.
03 - Heat a non-stick skillet over medium heat. Place a flour tortilla in the pan. Sprinkle evenly with one-quarter of the cheddar and mozzarella cheese blend.
04 - Arrange several fried onion rings over the cheese layer. Drizzle with 1 tablespoon sour cream and sprinkle with fresh chives if using. Top with another tortilla.
05 - Cook for 2-3 minutes until bottom tortilla is golden brown. Carefully flip and cook another 2 minutes until cheese is completely melted and the second side is golden.
06 - Remove quesadilla and let cool briefly. Cut into wedges and serve immediately with salsa, guacamole, and additional sour cream on the side.