01 - In a mixing bowl, gently mix ground turkey, red onion, garlic, Worcestershire sauce, smoked paprika, salt, and pepper without overworking.
02 - Divide the mixture into 4 equal portions and shape each into a patty about 1/2 inch thick.
03 - Heat a grill or skillet over medium-high heat and lightly oil the surface.
04 - Cook patties 5 to 6 minutes on each side until reaching an internal temperature of 165°F.
05 - Place a slice of Swiss cheese on each patty during the last minute of cooking and cover until melted.
06 - Toast the burger buns cut side down until lightly golden.
07 - Spread mayonnaise or Greek yogurt and Dijon mustard on bottom buns if desired; layer lettuce, turkey patty with cheese, avocado slices, tomato, and sprouts. Top with upper bun.
08 - Serve immediately for best freshness.