Bake baguette on an ungreased baking sheet 10 minutes or until warm.
Meanwhile, stir together mayonnaise and sriracha in a small bowl. Stir together carrots and fish sauce in a separate bowl.
Split baguette horizontally.
Cut each half into 3 (6-inch-long) pieces.
Spread cut sides of bread with mayonnaise mixture.
Layer bottom halves with Slow-cooker Mustard Barbecued Pork, Pickled Peppers and Onions, serrano pepper slices, carrot mixture, and cilantro to taste. Top with remaining bread slices.