Heat the cooking oil in a pot.
Saute the shallots, garlic and tomatoes until softened.
Add the chicken and bay leaf.
Pour in a tablespoon of fish sauce and a quarter teaspoon of ground pepper.
Cook, stirring often, until the chicken is no longer pink and the mixture is starting to turn dry.
Add the carrot, chayote and potato cubes.
Pour in the chicken bone broth and bring to the boil.
Taste and add more patis and ground pepper, as needed.
Cover the pot, lower the heat and simmer until the vegetables are done, about 15 minutes.
Taste the broth one last time and adjust the seasonings as needed.
Serve the chicken picadillo soup garnished with cilantro.