01 - In a mixing bowl, combine ground turkey, chopped onion, minced garlic, chopped parsley, smoked paprika, cumin, salt, and black pepper. Mix gently until ingredients are just blended.
02 - Divide the mixture into four equal portions and shape each into a patty.
03 - Heat olive oil in a skillet or grill pan over medium heat. Cook patties 5 to 6 minutes on each side until golden brown and internal temperature reaches 165°F. Remove from heat and allow to rest briefly.
04 - In a bowl, mash avocados until mostly smooth. Fold in diced tomato, red onion, minced jalapeño if using, chopped cilantro, lime juice, salt, and black pepper. Adjust seasoning as desired.
05 - Lightly toast burger buns if preferred.
06 - Place lettuce leaves on bottom buns, add turkey patties, top each with a generous spoonful of guacamole, sliced tomato, and sliced red onion. Cover with top bun halves.
07 - Serve immediately while warm.