1 baguette, 15 to 18 inches long
1/4 cup hot sauce
2 ounces creamy blue cheese, such as Saga blue
1/4 cup mayonnaise or sour cream
3 boneless, skin-on chicken breast halves (about 1 1/2 pounds)
2 teaspoons chili powder
Kosher salt and freshly ground black pepper
6 tablespoons unsalted butter
1 to 2 stalks celery
1/2 bunch watercress