Begin by preparing the pickled vegetables. In a medium bowl, mix the rice vinegar, water, sugar, and salt until the sugar and salt dissolve. Add the julienned carrots and daikon radish, then let sit for at least 30 minutes to pickle. Stir occasionally to ensure even pickling.

While the vegetables pickle, prepare the sandwich filling. Slice the pork belly or grilled chicken into thin strips. If using pork belly, briefly pan sear the slices to enhance flavour and caramelization.

In a small bowl, mix the mayonnaise with soy sauce (and sriracha if you prefer some heat). This creates a savoury spread that balances the sandwich flavors. Adjust the seasoning if necessary to match your taste preference.

Preheat your oven to 350°F (175°C) to warm the baguettes. Slice each baguette lengthwise, keeping one side attached, and warm in the oven for about 5 minutes. This step brings out the baguette's light, crispy texture, essential for an authentic Bánh Mì experience.

Once the baguettes are warm, spread a generous layer of the mayonnaise mixture on each side of the bread. For an authentic touch, add a layer of pâté if desired.

Layer the sandwich fillings. Start with slices of pork or chicken, then add a handful of pickled vegetables, cucumber slices, and thin slices of jalapeño or chili (for a hint of spice). Fresh cilantro sprigs go on top, providing a fragrant finish.

Close the baguettes gently, pressing slightly to hold the fillings in place. For a traditional look, wrap each sandwich in parchment paper, pressing it lightly to set the fillings.

Serve the Bánh Mì immediately, with extra pickled vegetables on the side if desired. Enjoy the sandwich warm for the best contrast between the crisp baguette, savoury fillings, and vibrant pickles. A hint of fresh chili sauce on the side can enhance each bite for those who like additional heat.