Yes, it seems like I am cooking all dishes for pregnant women, but somehow I love these dishes. I have tried and tested and refined this so many times till I got it right. Somehow, many seems to be fearful to try to cook this, I hope this will demystify the dish.
Ingredients are relatively few:
Old ginger or Muntong ginger (about the size of a hand)
Good sesame oil
One pig trotter (get the front legs not the hind legs as the latter is way too fatty)
One packet of black beans
One small bottle of sweetened vinegar
One large bottle of black vinegar
Get your pig trotters from Sanbanto if you can, they have very good quality pork there. Start with 3 pots. One to boil the trotters (a must) to rid of the impurities or else you will get a stinky smell. Dry roast the black beans for 10 minutes till all are crackling and split. Boil to make hard boil eggs.
Once you see sufficient impurities on the trotters pot (after 10 minutes or so), remove and wash clean, set aside. Now boil the black beans in water for 15 minutes on high, a must to soften the beans sufficiently - the water will be so dark. Drain and set aside.
The coarsely sliced ginger, dump into a wok with 6 table spoons of sesame oil. Fry for 5 minutes.
Then add the drained trotters, aim is to brown them with sesame oil and ginger coating and to precook them as later you do not need to stew them for too long with vinegar (as your vinegar will evaporate if you do so for too long a period). The browning process should take another 5 minutes.
Add the bottle of sweetened vinegar and one bottle of black vinegar, the other bottle of black vinegar you need to keep in case to fine tune the final result, and it should look something like below. The secret here is do not use caster sugar as that would make it sickly sweet (even weakens your teeth). Throw in the black beans as well. Chop one roll of gula melaka and add to the stew. Gula melaka has a more rounded sweetness and better caramelisation without being too sickly sweet. Go on low fire for simmering for 45 minutes. Stir with soft hands every two minutes to make sure all pieces gets proper cooking.
Add the egg after 10 minutes of simmering when you don't have to stir so much as the eggs might break easily. After 30 minutes of simmering, taste to see if you need more gula melaka or the black vinegar to balance the taste.
End result. You can let it cool down and separate into 5 plastic containers, so it can last a few meals or you can give some away.