01 - Combine ground turkey, egg, oats, red onion, Dijon mustard, garlic, parsley, smoked paprika, salt, and black pepper in a large bowl. Mix gently until just combined, being careful not to overwork the meat.
02 - Divide mixture into 4 equal portions and shape each into a patty approximately 1/2 inch thick. Press gently to create even, compact patties that will hold together during cooking.
03 - Preheat a nonstick skillet or grill over medium-high heat. Lightly oil the surface if necessary to prevent sticking.
04 - Cook patties for 4-5 minutes per side until golden brown and fully cooked through, reaching an internal temperature of 165°F. Do not press down on patties while cooking to retain juices.
05 - Lightly toast whole wheat burger buns on the grill or in a toaster for added texture and to prevent sogginess from toppings.
06 - Build each burger by placing a lettuce leaf on the bottom bun, followed by the cooked patty. Spread Greek yogurt on the patty, then add tomato slices, red onion, and avocado. Top with the upper bun and serve immediately.