In a bowl or wide jar, combine the 120ml rice vinegar, 120ml warm water, 2 tbsp sugar and 1 tsp salt, stirring until both the sugar and salt have fully dissolved and the brine looks clear. Add the 150g carrot and 200g daikon matchsticks and press them down firmly so every piece sits under the brine. Leave them to pickle for at least 20–30 minutes at room temperature while everything else is prepared, or cover and refrigerate for longer if making ahead. Do not heat the brine or the vegetables at any point. They are ready when they taste bright, lightly sweet, lightly salty and sharply tangy but still snap when bitten. That cold, short soak is what seasons the vegetables right through while keeping the genuine crunch the whole bowl relies on.

If the pork is not already sliced, cut the 700g pork shoulder or tenderloin thinly against the grain, about 3–5mm thick, leaving no large or thick chunks. In a large bowl, combine the very finely minced lemongrass, 4 garlic cloves, shallot, 2 tbsp fish sauce, 1 tbsp soy sauce, 1 tbsp neutral oil, 1 tbsp sugar, 1 tsp black pepper and ½ tsp salt, adding the 1 tsp sesame oil if using. Add the pork and mix very thoroughly with your hands so every slice is coated in the aromatic paste. Cover and marinate for at least 30 minutes; tenderloin needs no more than 30–45 minutes, while shoulder benefits from 1–2 hours in the fridge if there is time. The marinade should smell strongly of lemongrass and garlic and taste savoury-sweet. That thin, cross-grain slicing is what keeps every piece tender and lets it cook fast enough to caramelise before it dries out.

As soon as the pork is marinating, rinse the 300g jasmine rice in cold water 3–4 times, swirling it with your fingers, until the water runs mostly clear, then drain well. Combine the rice, 375ml water and the pinch of salt, if using, in a medium saucepan and bring to a boil over medium-high heat. Stir once, cover tightly, reduce to the lowest heat and cook for 12–13 minutes, until the water has been absorbed and small steam holes dot the surface. Turn off the heat and leave it to rest, still covered, for 10 minutes without lifting the lid, then fluff gently with a fork. The grains should be fluffy and separate, never wet, sticky or mushy. That measured water and undisturbed rest is what gives the loose rice a composed bowl needs.

While the rice cooks, stir the 1½ tbsp sugar into the 2 tbsp warm water in a small bowl until it has completely dissolved. Add the 3 tbsp fish sauce, 2 tbsp lime juice, the finely minced garlic clove and the sliced small red chilli, and stir again. Taste carefully and adjust only if needed: a little more lime for brightness, a little more sugar if it tastes too sharp, a splash more water if it is too intense, or a few drops more fish sauce if it needs depth. The finished sauce should taste salty, tangy, lightly sweet and punchy, with no single element dominating. Set it aside so the garlic and chilli can infuse while the pork cooks. That careful balance is what lets a small drizzle season the whole bowl.

While the rice rests, lift the pickled carrot and daikon from the brine and drain them lightly in a sieve, leaving them moist but not dripping. Pick the 20–25g cilantro into small sprigs and pick the mint leaves, if using, discarding any tough stems. Thinly slice the 1–2 red chillies and cut the lime wedges. Slice the cucumber thinly last, as close to serving as possible, so it stays cold and crisp. Arrange every component in separate small piles or bowls beside the stove, ready for assembly. Once the pork starts cooking, there is no time to stop and chop. That advance preparation is what allows the pork to go straight from the pan into the bowls while it is still genuinely hot and glossy.

Heat a large skillet, frying pan or grill pan over high heat for 2–3 minutes, until very hot and just beginning to smoke; add 1–2 tsp extra neutral oil only if the pan looks dry. Add about a third of the pork in a single layer and let it sear undisturbed for about 1 minute, then turn and keep cooking for 2–4 minutes in total per batch, until browned in spots, lightly caramelised and just cooked through with no pink in the thickest slice. Let a few edges char slightly for a grilled banh mi feel. Transfer to a plate, let the pan reheat fully and repeat with the remaining batches. If liquid pools heavily, the batches are too large. Remove tenderloin as soon as it is cooked, while shoulder can take stronger browning. Return all the pork for 30–60 seconds and toss. That brief final toss is what evens out the seasoning and gloss across every slice.

Divide the warm, fluffy rice between 4 bowls. Top each bowl with a quarter of the hot lemongrass pork, then arrange the pickled carrot and daikon, cucumber slices, cilantro, a few mint leaves if using and the sliced red chilli in separate sections around it, keeping the bowl visually sectioned rather than tossed. Drizzle each bowl lightly with about 1–2 tbsp of the nước chấm-style sauce, just enough to season and brighten, and serve the rest on the side. Tuck lime wedges alongside. If using the optional finishing touches, add only a few chopped peanuts or a small drizzle of chilli sauce or chilli oil. The rice should look moist where the sauce touches it, never soupy. That restrained finish is what keeps the bowl reading clearly as banh mi-inspired rather than as a different style of rice bowl.