Heat the oil.
Brown the pork.
Add the garlic, ginger, chilies and shallots. Season with fish sauce and dark brown sugar.
Saute for about a minute the add the chayote and pour in the broth.
Drizzle in more fish sauce.
Bring to the boil, cover the pan and simmer for about 10 minutes or until the chayote strips are done, still firm and definitely not mushy.
Taste, adjust the seasonings, as needed. Top with snipped cilantro (and more finely sliced bird's eye chili, if you like) before serving.