Place the sugar in a small, heavy saucepan over medium heat; cook 5 minutes or until golden (do not stir). Add water and fish sauce (mixture will splatter); remove from heat.
Heat 1 teaspoon oil in a large skillet coated with cooking spray over high heat. Add pork, and cook 4 minutes or until browned on all sides. Remove pork from skillet. Stir broth into skillet, scraping skillet to loosen browned bits. Return pork to pan; add the caramelized sugar mixture, black pepper, and cinnamon stick, and bring to a boil. Cover, reduce heat, and simmer 1 1/2 hours or until pork is tender. Remove from skillet, and keep warm.
Heat 1/2 teaspoon oil in skillet; add green onions. Sauté 2 minutes or until lightly browned. Add to pork mixture; keep warm.
Combine shredded lettuce, rice vinegar, basil, and cilantro in a large bowl, and toss well. Serve pork mixture over lettuce mixture.
Made to recipe except used brown sugar (so the sauce was darker) and cooked the pork in advance to reheat in the microwave the next day while the onions quick-browned. Went over well as lunch on a tv-football-weekend.
