Cut the pork bones into pieces approximately 5 cm long and wash well. Bring a large pot of water to a rolling boil and add the bones. Boil for 5 minutes.
While the bones boil, prepare the vegetables: wash and peel the tomatoes, then cut them into quarters lengthwise and halves crosswise. Remove the stems from the red peppers, wash them, cut open lengthwise, flatten, and remove the seeds. Cut each opened pepper in half lengthwise again, then slice crosswise into approximately 1 cm wide pieces.
Add the tomatoes, peppers, instant chicken broth, and some of the cooking water to a blender. Purée for 1 minute at the highest setting.
Drain the water from the boiled bones and rinse thoroughly. Return the bones to a clean pot. Add the puréed mixture and remaining water to the pot.
Cut both ends off the onion and garlic cloves, peel them, and cut into rough pieces. Heat the peanut oil in a pan over medium-high heat. Add the onion and garlic, roasting for approximately 5 minutes until light brown. Transfer to the pot with the bones.
Wash the carrot, cut off both ends, peel, and grate with a coarse grater. Wash the green chilli and cut into thin slices, leaving the seeds in and discarding the stem.
Wash the fresh lemongrass and remove the hard bottom stalk and any brown or withered leaves. Use only the white to light green parts. Cut into pieces approximately 8 cm long, removing outer green leaves if needed. Gently crush the lower half of each piece with a hammer, keeping the stem intact.
Wash, peel, and thinly slice the ginger. Wash the kaffir lime leaves and reserve.
Add the grated carrot, sliced green chilli, lemongrass pieces, sliced ginger, kaffir lime leaves, cinnamon stick, dark soy sauce, light soy sauce, and oyster sauce to the pot. Cover with a lid and simmer over medium-low heat for 3 hours. Remove from heat and let cool for 10 minutes. Strain through a fine sieve. Remove the meat from half the bones and add to the broth. Lightly clean the remaining bones and add them to the broth as well.
Heat the soup over medium heat until hot, without boiling. Divide among serving bowls and serve with white rice.