2) Heat the griddle to high. Remove the pork from the marinade and arrange on the griddle. Reserve the marinade. Griddle for 5 minutes per side for medium doneness. Remove the pork from the griddle to a platter.
3) Pour the reserved marinade into a small saucepan over a medium heat. Bring to a boil and let reduce until it starts to thicken, about 10 mins. Drizzle the pork with the reduced marinade.
4) In a nonreactive bowl, preferably glass, add the rice wine vinegar, the remaining brown sugar, mirin and the remaining soy sauce, and mix until the sugar is dissolved. Add the cucumbers and leave to marinate for 10 to 15 mins.
5) Heat a large heavy saute pan over a low heat. Drizzle olive oil on the cut sides of the rolls and arrange, cut side down, in the pan to toast.
6) In a small mixing bowl, add the mayonnaise, hot sauce, oyster sauce and sesame oil, and mix to combine. Leave to sit for 5 minutes, then coat each side of the rolls with about 2 tbsp of the spicy mayonnaise.