Blanch the bean sprouts for a minute, then set them aside to drain. Boil the noodles in plenty of water for five minutes, then drain them. Next, cook the ground pork in a saucepan over medium heat until it begins to brown. Add chicken stock, dried shrimp and fish sauce, stir, and bring the mixture to boil. Meanwhile, chop the garlic and fry it in a tablespoon of vegetable oil until it is crisp. Place the blanched bean sprouts in the bottom of a large serving bowl. Top with the cooked noodles. Pour the fried garlic and its oil over top of the noodles. When the chicken stock mixture boils, tear the lettuce leaves into strips, add them to the stock, immediately remove the stock mixture from the stove, and pour it over the noodles and bean sprouts. Garnish with pork slices, green onions and corriander leaves. Sprinkle in the sugar, peanuts and chile flakes and serve immediately.