I found a video of the bamboo fish being prepared, and if anyone's interested you can watch it here:
https://www.douyin.com/video/6933060159459675392
There are variations of the prep method where the pork fat netting isn't used (an article cites that modern people are wary of cholesterol), but the above video does use it, and the chef also used the rotating grill method exactly like the manga says.