My version of the marinade/pork:
1/2 cup brown sugar
Juice of 1 lime
2 Tbs fish sauce
3 Tbs soy sauce
Red chili flakes
1 Tbs grated ginger
2 cloves chopped garlic

Simmer all the above just until the sugar melts. Sear pork loin a hot frying pan first, then put on a baking sheet w aluminum foil into the oven at 325 for 35-40 minutes. Glaze the meat with half the sauce after you sear it (just before you put it in the oven) then glaze it with the rest of the sauce about 10 minutes before it's done.

TOPPINGS
Top noodles with chili sauce, pork, sprouts, cilantro, min, green onion, cucumber, pickled carrot/radish, crush peanuts, lettuce.

VIETNAMESE SAUCE
Serve more chili sauce on side: 2 cloves garlic, chopped chile, 4tbs white vinegar, 4tbs white sugar, 1tbs fish sauce, lime juice, 6tbs water.