In a small bowl combine the ground turkey, salt, pepper, feta and green onions. Mix with your hands to combine everything. Form into 5 football shaped burgers. Set aside while you preheat your grill.
Preheat your grill to 375°F. Clean and oil the grates.
Grill the burgers 5-6 minutes per side, or until cooked to 165°F. Remove the burgers from the grill and lightly grill the pitas, 1-2 minutes per side.
To assemble: cut the grilled pita pockets in half so they can fold over themselves like a sandwich. On the bottom of the pita place 4-5 slices of the avocado, then the burger followed by a generous amount of tzatziki. Top off with a couple leaves of the butter lettuce and the other half of the pita.
Serve warm.
Recipe Courtesy of Megan Mitchell