Preheat the oven to 375. Add chicken breast to a baking dish and thoroughly coat in the hot sauce. Cook for about 30 min, depending on how thick your breasts are. Flip halfway through. When cooked and cooled, pull chicken and add to a large bowl.
Add a brioche bun to each cocotte and using a serrated blade, hollow the centers out of the rolls. Break the middles into smaller pieces and add to a baking sheet (they are great for breadcrumbs).
Heat ¾ cup hot sauce in a pot, with red curry paste and butter. Season with salt and pepper and stir until smooth and combined. Add to the bowl of pulled chicken along with blue cheese, mozzarella and diced celery. Stir until combined.
Stuff inside brioche buns until overflowing and top with more cheese and green onions. Bake for about 15 min or until tops start to brown. Broil for about 3-4 min until nice and golden brown. Add in the baking sheet of the brioche middles for those last 3-4 min on broil.
Top with more green onions and breadcrumbs. Enjoy!