Heat oil in pot. Add garlic and fry for 30 seconds. Add in the prawn shells and head, brown sugar and sauté until they are fragrant and the colour changes to orange.
Add water and bring to a boil and let it simmer for 20 minutes.
Strain the stock and discard the shells.
Pour the prawn stock into another clean pot. Bring it to a boil.
Add the blanched pork ribs, star anise, cloves, white peppercorns, rock sugar, fish sauce, salt. Bring to boil and let it simmer for 1 ½ hours or until the ribs are tender but not falling apart.
Once the soup base isdone cooking, taste and add more salt, sugar and pepper if needed. Add the dark soya sauce for colour if needed.
Blanch the prawnsyou will be serving with the noodles briefly in the soup base until they turn pink and cook through. Remove and set aside.
Using the boiling soup base, blanch the pork loin till cooked. Remove and cut the pork loin into thin slices.
Bring a small pot of water to a boil. Then portion out the noodles, bean sprouts and kangkong and blanched them.
Transfer into serving bowls.
Top with prawns, pork slices.
Ladle hot soup over, then garnish with shallots. Serve with cut chili and chili powder as condiments.