In a medium bowl, combine the ground turkey, finely diced red onion, finely diced celery, garlic powder, sea salt, and black pepper.
Gently fold in 1 tablespoon of the buffalo sauce, being careful not to overwork the meat to keep the texture light.
Form the mixture into two equal-sized patties, pressing a small indent into the center of each to ensure even cooking.
Heat the avocado oil in a cast-iron skillet over medium-high heat until shimmering.
Place the patties in the skillet and sear for 5-6 minutes per side until the internal temperature reaches 165°F.
During the last minute of cooking, top each burger with the blue cheese crumbles and cover the pan briefly to allow the cheese to soften.
Drizzle the remaining tablespoon of buffalo sauce over the patties.
Serve each burger inside two butter lettuce leaves, using them as a sturdy wrap for a fresh, clean finish.