Preheat your oven to 375 F. In a large pot, pour in the beef broth, add in the spices and bring to a rolling boil and then lower the heat and let it simmer and bring it back to a boil when ready to serve the noodle. In another large pot, bring a water to a boil and cook the noodles and cook until soft, but not mushy, about 3-4 minutes. Drain off the water and set aside
Wash the duck in a clean cold water and pat dry with paper towel. Place on a roasting pan and rub the duck with salt and pepper. Place it into the oven and roast until it's cooked through, about 45 minutes or longer. When the duck is done, save the juice from roasting the duck and pour it into the pot where you boil the broth. Turn on the broiler on high and broil the duck until the skin is brown, but not burnt. Remove from the oven and cover with foil and let rest for about 10 minutes before slicing
In a individual serving bowl, portion out the noodles, the duck slices. Top with bean sprouts, few sprigs of basil leaves, mint leaves, cilantro and sprinkle with some spring onion. Ladle the hot soup over until it covers the noodles and serve immediately