Put chicken in the saucepan
Add the chicken legs and one stalk of lemongrass to a medium saucepan with 2 cups of water. Having brought it to a boiling point, you need to lower the heat and allow it to simmer until the meat is very tender or for approximately 15 minutes.
Remove the pan
Remove the pan from the heat and let it cool enough so that it can be handled. Save the broth and shred the meat after removing the chicken legs.
Strain the broth into a large pot
Grab a large pot and strain the broth into it. You can now insert ginger, coconut milk, chiles and the remaining one stalk of lemongrass. Without boiling, you need to cook them for about 2 to 3 minutes.
Add chicken in the pot
You can now add the breast and leg meat in the pot and allow it to cook while you stir it. Having added the green onions and mushrooms, you are required to cook them for another three to four minutes.
Add other ingredients
Once your Thai coconut soup is nicely cooked, you should add lime juice, fish sauce, salt and pepper. Sprinkle some cilantro on top of the soup.