When a soup is described as a "yam", it means that everything is just tossed into the stock as it simmers. This soup is also sometimes called Kaeng Jued Wunsen (Kaeng Jued implies a rather bland soup -- by Thai standards!). This can be made with a variety of ingredients, but the most interesting are probably pork (as here), beef, chicken, shrimp, meat balls, fish balls, shrimp balls, or one of the various Thai sausages, as well as vegetarian options (for a quick veggie variation try marinating some tofu in dark sweet soy sauce for about 3 hours and then using that instead of the pork).
For 4 Person(s)
Mix the marinade ingredients, mix with the ground pork, and make the pork into small meat balls, then set aside and leave to marinate for 3 or 4 hours.
Soak and drain the noodles.
Bring the stock to a boil and add all the ingredients except the noodles, and continue to boil until the meatballs are cooked through, when they will float. Remove from the heat, pour into a serving bowl and add the noodles (note the immersion in the near boiling soup is enough to cook the noodles).