Make the pickled vegetables: Put the carrots, cucumbers and jalapeno in a bowl. Heat the rice vinegar and fish sauce in a saucepan, then pour over the vegetables. Add a pinch each of salt and pepper and set aside, stirring occasionally, while you prepare the noodles and pork.
Bring a small pot of water to a boil; remove from the heat, add the noodles and let stand 8 minutes. Drain the noodles and rinse under cold water, then snip into smaller pieces with kitchen shears.
Meanwhile, season the pork lightly with salt and pepper. Heat 1 tablespoon vegetable oil in a medium skillet over medium-high heat. Add the pork and cook until just cooked through, 3 to 4 minutes per side. Brush each chop with hoisin sauce; turn and cook 30 seconds. Brush with more hoisin sauce, turn and cook 30 more seconds. Remove to a cutting board and let rest 5 minutes, then thinly slice.
Divide the noodles among bowls. Strain the pickled vegetables, reserving the liquid. Stir 1 tablespoon hoisin sauce and the remaining 2 tablespoons vegetable oil into the reserved liquid; drizzle over the noodles. Top with the pork, pickled vegetables, lettuce and herbs.
Per serving: Calories 476; Fat 20 g (Saturated 4 g); Cholesterol 78 mg; Sodium 618 mg; Carbohydrate 38 g; Fiber 4 g; Protein 36 g