First prep your cha lua, cucumbers, and jalapeño. Thinly slice all these ingredients and set aside in the fridge.
Combine all the ingredients for the lemongrass pork in a bowl. Make sure the pork is coated in the marinade. Let the pork marinate for at least 30 minutes.
Heat a grill pan or regular pan over high heat. Cook the pork for 1-2 minutes on each side until brown. Set aside.
Put together your banh mi. Cut the baguette about halfway through length wise, so you can open it like a Subway sandwich. Smear mayonnaise on one side of the baguette and pate on the other side of the baguette. Add the lemongrass pork, cha lua, cilantro, cucumbers, pickled carrots, pickled daikon, and jalapeño to the baguette.