Heat the olive oil in a large skillet over medium-high heat. Add the ground chicken and cook until browned, breaking it up with a spoon as it cooks. Add the carrot, celery and onion. Season with salt and pepper. Cook until tender, 7-8 minutes. Add the garlic and cook for another minute.
Meanwhile, combine the red wine vinegar, brown sugar, Worcestershire sauce, hot sauce, tomato sauce and chicken stock in a small bowl and whisk to combine. When the vegetables are tender, pour the sauce in and stir to combine. Cook an additional minute or two, until the mixture is thickened.
Serve the chicken mixture on top of the toasted buns. Top with crumbled blue cheese.
