Pan cook chicken feet in a cast iron pan until they brown. Mailliard reaction is great for complex flavor. Another option is to roast them in a pan until they brown and the bones soften a bit
Add aromatics to the pan after some of the chicken fat has rendered—garlic and ginger should be sliced very fine and allowed to turn golden in the pan
Transfer to a large stew pot, then add cold water to the cast iron pan while it’s still hot to deglaze, transfer the liquid to the stew pot
Make sure that the chicken bones are well-covered, then add lemon juice, about half of the salt, and the Thai chilies and bay leaf, cover and bring to a boil, then reduce heat so that broth stays at a consistent simmer.
Check on it every hour to make sure not too much water is evaporating and add more liquid if necessary
After hour two, adjust salt to taste and add pepper
Cook as long as you want! It’ll get better if you can leave it overnight. Comes out quite gelatinous, very rich.