Pickled Cucumber and Carrot: Mix the rice vinegar, sugar and sea salt in a small saucepan. Bring the mixture to the boil until the sugar dissolved and let cool to room temperature. Place the carrot, cucumber and chilies in a mixing bowl and add in the sugar and vinegar mixture. Chill for about 20 minutes before serving.
Sauce: Combine all sauce ingredients to mix. Set aside.
Spicy Lemongrass Chicken: Season the chicken thighs with sea salt and black pepper. Heat a large cast-iron pan over high heat and add 1 tablespoon of peanut oil.
Add the chicken and fry both side until golden brown. Turn the heat to medium and mix in the sauce, press down the chicken meat with a spatula and continue to cook until the sauce thickens and becomes caramelized. Remove from the heat and let cool slightly before slicing.
Sandwich: Lightly toast the baguettes and fill with chicken slices with its sauce, pickled vegetables, green chili and assorted herbs. Serve immediately.