The evening before, soak the dry bamboo shoots in a large bowl of water with 1 tablespoon salt. The water will turn brown, so occasionally wash the bamboo shoots and change the water (at least 3-4 times). When ready to cook, drain and squeeze dry the bamboo shoots (the water should run clear) and cut into strips (About 2 inches long).
Boil water in a large pot, add the dry bamboo shoot and boil for 30 minutes. Drain and rinse again until the water is clear (no hint of yellow). Heat the oil in a frying pan, add the chopped shallots, then the bamboo shoots and stir fry. Add the seasoning: chicken powder, sugar, salt and pepper and taste. Set aside.
Time saving tip: The morning of the meal, soak the rice vermicelli in a large bowl of water (this will reduce the cooking time for 8-10 minutes to around 1-2 minutes)
Put the sliced onion and ginger in a toaster oven and broil for around 5 to 10 minutes, so they'll be slightly charred and fragrant, but don't let it burn.
In instant pot, put the duck legs, slightly charred onion and ginger, sugar and 8 cups of chicken broth. Set on high pressure for 9 minutes (if you prefer more tender duck, set for 10 minutes), close the valve.
In the meantime, boil water and cook the soaked rice vermicell and rinse with running water. Divide among 4 bowls. Add the fried bamboo shoots in each bowl. Any leftover bamboo shoots can be wrapped and frozen for up to 2 months.
Wash the vegetable and herbs, shredd the cabbage, cut the limes and chili. Display the garnishes with the herbs (Vietnamese coriander and mint) on a platter
Prepare the dipping sauce: Crush the garlic, ginger and chili in a mortar and pestle (or Magic Bullet). Mix the fish sauce, sugar and lime juice. Add the garlic, ginger and chili. Divide into 4 dipping bowls.
When the IP is ready, manually release the steam by opening the valve. When the steam has subsided, open the lid. Immediately remove the duck legs and let cool. When cool, debone and cut into bite size and divide among the 4 bowls of rice vermicelli.
Taste the broth and adjust the seasoning if necessary by adding chicken powder, fish sauce or sugar. You could turn on the Saute function on the IP to heat the broth.
Laddle the broth over the duck, bamboo shoot and vermicelli bowl, sprinkle some chopped green onions and coriander on top. Serve with the garnish vegetable and herb and dipping sauce.