I learned this pumpkin soup recipe from my mom. I used pork neck bones and a kabocha pumpkin today, but you could use other cuts of pork or a different pumpkin as well.
To a large soup pot, add the pork neck bones, garlic, salt, sugar, and MSG (if using). Cover with water until the bones are completely submerged by about 1 inch of water. Bring to a boil and reduce to a simmer. Cook for 1 hour and 45 minutes. During this time, periodically skim off the scum that rises to the surface of the water.
Remove the skin and seeds from the pumpkin. Cut into ½-inch thick slices and add to the soup. Cook for 10-15 minutes or until the pumpkin is soft.
At this point, the soup should be ready to serve. I like to taste the soup and adjust any flavoring as needed. If it's not salty enough, you can add a teeny bit of salt at a time until you're satisfied.
I like to serve this with cilantro, steamed rice, and chili oil.