01 - Combine ground turkey or chicken, egg, oats, red onion, Dijon mustard, garlic, parsley, smoked paprika, salt, and black pepper in a large bowl. Mix gently until just combined—avoid overworking the meat.
02 - Divide mixture into 4 equal portions and form each into a patty approximately 1/2 inch thick.
03 - Heat a nonstick skillet or grill over medium-high heat. Lightly oil the surface if necessary.
04 - Grill patties for 4-5 minutes per side until golden brown and fully cooked, reaching an internal temperature of 165°F.
05 - Lightly toast whole wheat buns if desired.
06 - Layer each burger starting with lettuce leaf on the bun base, followed by patty, Greek yogurt, tomato, onion, avocado if using, and top bun.