01 - In a large bowl, combine ground turkey, finely chopped onion, minced garlic, egg, breadcrumbs, chopped parsley, salt, black pepper, and paprika. Mix gently until just combined, avoiding overmixing.
02 - Divide the mixture evenly into four portions and form each into a patty.
03 - Heat olive oil in a nonstick skillet or grill pan over medium heat. Cook each patty for 5 to 6 minutes per side until golden brown and internal temperature reaches 165°F (74°C).
04 - Lightly toast the whole wheat buns if desired.
05 - Spread light mayonnaise or Greek yogurt and Dijon mustard on the cut sides of the buns. Layer romaine lettuce, cooked turkey patty, sliced avocado, tomato, and red onion. Top with the bun lid.
06 - Serve the assembled turkey burgers immediately while warm.