Use a kitchen mallet to break open the black cardamom pods. Extract the black cardamom seeds. Place the black cardamom seeds and coriander seeds together in a pan and heat over medium heat until they are toasted and aromatic.
Peel and slice the ginger and turmeric. Place in a pan and heat over medium heat until they are toasted and develop a slight char.
Place the toasted seeds in your mortar and pestle and pound until they are finely ground. Add the toasted ginger and turmeric and pound until a fine paste is formed. Add the red curry paste and pound everything together until the curry paste is smooth.
To Make the Curry Soup:
Open a can of coconut milk and gently scoop the top layer of cream (~½ cup) into a large wok. Heat over medium high heat until you start to see an oily sheen.
Add the khao soi curry paste and stir into the coconut cream. Cook until the curry paste has completely absorbed the coconut milk and is aromatic. Then add the chicken drumsticks and coat them in the curry paste.
Add the rest of the coconut milk, chicken broth, and water. Allow the curry broth to simmer for roughly 45 minutes to 1 hour, uncovered, until the chicken is cooked through.1
Once the chicken is fall-off-the-bone tender, season the curry soup with palm sugar, thin soy sauce, and dark soy sauce.
To Make the Fried Chili Oil:
Follow these directions to make fried garlic. Remove from the oil, then use the same method to make fried shallots (be aware that the shallots take longer to fry than the garlic). Remove the fried shallots from the oil.
Add dried chilis to the hot oil and allow to fry until they are dark red. (This will occur quickly, be prepared to remove them almost immediately).
Pound the fried garlic, fried shallots, and fried chilis together in the mortar and pestle. Add back 2 Tablespoons of the frying oil to form the fried chili oil.
To Serve the Khao Soi:
Boil 12 ounces of egg noodles until they are al dente, following package instructions.
Fry the remaining 4 ounces of egg noodles in oil until golden brown.
Place the boiled noodles in the bottom of the bowl and scoop a chicken drumstick and the curry soup over the top. Top with a handful of fried noodles.
Serve with shallots, pickled mustard greens, lime slices, fried chili oil, and a stalk of cilantro. Enjoy!
Notes
The curry broth will condense down and become rich during the time that it simmers. You may need to add 1-2 more cups of water if it becomes too thick while cooking.