To achieve ultimate cracklings and juicy roasted belly pork, these are my views after attempting making them again. It is not the recipe that is important. The most important factor is to have the proper oven to roast and grill the skin until it crackles evenly. Choosing the right piece of belly pork is equally important.
A turbo oven with the fan and heating elements on the cover is most desirable. I do not own one, so when i bought a new microwave oven which has 2 grill functions - top and bottom, i tried making 'siew yoke' again. The result was so good and the skin crackled evenly all due to the turntable which rotates. When there is a failure in anything, i will tend to put the blame on the utensils - like the saying goes - 'A bad workman blames his tools'. In this case, the correct utensil and equipment are the prime factor for success.
Choosing the proper piece of meat for this type of roasting is important too. I found that the lean and fat have to be very evenly striped to ensure a flat surface of skin which aided it to crackled. An uneven piece, when roasted will tend to buckle. (note that the piece of meat at the back of picture is all buckled up, it was due to a strip of lean meat which is thicker than the rest).
The recipe: The recipe remains the same in Roast Belly Pork http://lilyng2000.blogspot.com/2005/10/roast-belly-pork.html