In a medium mixing bowl, combine the ground turkey, finely diced celery, buffalo sauce, garlic powder, onion powder, sea salt, and black pepper.
Gently mix the ingredients by hand until just incorporated, taking care not to overwork the meat to ensure the burgers stay juicy.
Form the mixture into two equal-sized patties, approximately 1-inch thick, and press a small thumbprint into the center of each to prevent bulging during cooking.
Heat the avocado oil in a cast-iron skillet or heavy-bottomed pan over medium-high heat until shimmering.
Add the patties to the skillet and sear for 5 to 6 minutes on the first side until a golden-brown crust forms.
Flip the burgers and cook for another 5 minutes, or until the internal temperature reaches 165°F.
During the final minute of cooking, sprinkle the blue cheese crumbles evenly over the patties and cover the pan with a lid to melt the cheese slightly.
Lay the large romaine lettuce leaves on a plate to serve as the 'buns' and place one patty on each leaf.
Top with the red onion slices and an additional dash of buffalo sauce if desired before folding the lettuce around the burger.