Heat a 12-inch skillet over medium-high heat. Add the vegetable oil. Sprinkle both sides of the chicken with some salt and pepper, the brown sugar, paprika and cayenne. Sear both sides of the chicken in the skillet until golden, about 4 minutes. Add in the wing sauce, bring to a simmer and finish off in the oven until the chicken registers 165 degrees F on an instant-read thermometer, about 15 minutes. Let cool, and then pull the meat with your hands or two forks. Adjust the seasoning if necessary, add the butter if using, and place back in the oven at BROIL until crusty and caramelized on top, about 4 minutes.
In a bowl, the combine carrots, celery and tomatoes, and season with salt and pepper. Mix until combined.
Cut the French loaf horizontally. Place an even layer of blue cheese crumbles on the bottom, then the chicken and then the veggies. Serve with a side of Homemade Ranch Dressing.
Homemade Ranch Dressing:
Mix the mayonnaise, buttermilk, garlic, dill, honey, salt, mustard and pepper in a bowl. Store in an airtight container.
The chicken can also be seared on a grill pan, then transferred to an oven-proof baking dish.