Vietnamese Beef Banh Mi

Instructions

1. Marinate the beef
   In a medium bowl, combine fish sauce, soy sauce, brown sugar, minced garlic, and lemongrass. Add the thinly sliced beef, mix well to coat, and marinate in the refrigerator for at least 30 minutes, up to 4 hours.
2. Prepare the baguettes
   Preheat oven to 350°F (175°C). Slice the baguettes lengthwise, but not all the way through, leaving a hinge. Warm them in the oven for 5 minutes until slightly crisp on the outside but still soft inside.
3. Cook the beef
   Heat a large skillet over high heat. Add the marinated beef in a single layer (cook in batches if necessary) and sear for 2-3 minutes per side until caramelized and cooked through. Remove from heat and let rest for 5 minutes before slicing thinly across the grain.
4. Prepare the sauce
   Mix the mayonnaise and Sriracha sauce (if using) in a small bowl until well combined. Spread this mixture on the inside of both sides of the baguettes.
5. Assemble the sandwiches
   Layer the cooked beef slices on the bottom half of each baguette. Top with pickled daikon and carrot, cucumber slices, jalapeño slices, and a generous amount of cilantro leaves.
6. Serve
   Close the sandwiches, pressing slightly to compact the fillings. Cut each sandwich in half diagonally if desired, and serve immediately while the bread is still warm and the beef is hot.