How to Make It
In a medium skillet, heat the oil. Season the chicken breasts with salt and pepper and add them to the skillet, skin side down. Cook over moderately high heat until the skin is browned and crisp, about 4 minutes. Reduce the heat to moderate. Turn the chicken breasts over and cook until white throughout, about 5 minutes longer. Transfer the chicken breasts to a carving board and let rest for 5 minutes. Slice the chicken crosswise 1/3 inch thick.
Spread the chile-garlic sauce on the cut sides of the baguettes and spread mayonnaise on top. Fill the sandwiches with the watercress, chicken, tomatoes and carrots and serve.