Make the Pickled Vegetables:
In a small saucepan, heat the rice vinegar, water, sugar, and salt until the sugar dissolves. Pour the mixture over the carrots and daikon in a bowl. Let sit for at least 30 minutes or refrigerate for up to 24 hours.
Prepare the Protein:
In a mixing bowl, combine soy sauce, fish sauce, sesame oil, sugar, garlic, and ginger. Add the pork, chicken, or tofu, coating evenly. Let marinate for 20–30 minutes.
Cook the Protein:
Heat a grill pan or skillet over medium heat. Cook the marinated protein until fully cooked and slightly caramelized, about 3–5 minutes per side.
Prepare the Baguettes:
Slice the baguettes lengthwise, leaving them hinged. Lightly toast them in the oven or on a grill until warm and crispy.
Assemble the Sandwiches:
Spread mayonnaise mixed with sriracha on the inside of each baguette. Layer with cooked protein, pickled vegetables, fresh cilantro, cucumber slices, and jalapeños if desired.
Serve:
Serve immediately and enjoy the explosion of flavors and textures!