(See cooking tip.) Preheat the oven to 220C, fan-forced. Line an oven tray with baking paper. Pat the pork belly dry with paper towel. Rub with 2 tsp oil and 1 tsp salt. Put the pork, skin-side up, on the lined tray. Roast for 40 mins or until the skin starts to blister.
Step 2 — Finish pork belly
When the pork belly has roasted for 40 mins, reduce the heat to 180C and roast for a further 25 mins or until the pork is cooked through. Remove from the oven and rest for 10 mins.
Step 3 — Prep slaw
Meanwhile, crush or finely chop the garlic. Thinly slice the onion and celery. Shred the carrot using a julienne peeler or coarsely grate with a box grater. Reserve a few coriander leaves, then finely chop the remainder, including the stems. Put the onion, celery, carrot and chopped coriander in a large bowl. Stir in 2 tsp white vinegar until combined.
Step 4 — Toast coconut
While the pork is resting, put the coconut in a cold medium deep frypan over medium heat. Toast, tossing, for 2-3 mins until evenly golden. Remove from the pan and reserve the pan. Enclose the tortillas in foil. Put in the oven for 8 mins or until softened and warmed through.
Step 5 — Make adobo sauce
Combine the stock powder, 2 tbs water, 1½ tbs white vinegar, 1 tsp sugar and 1 tsp soy sauce in a bowl. Heat 1 tsp oil in the reserved pan over medium heat. Cook the garlic for 1 min or until fragrant. Stir in the sauce mixture and bring to a simmer. Cook, stirring, for 1 min or until slightly thickened. Remove from the heat.
Step 6 — Assemble and serve
Transfer the pork belly, skin-side down, to a chopping board. Cut into 2cm chunks. Add to the adobo sauce and stir well to coat. Divide the tortillas among plates. Fill with the pork and slaw. Scatter with the coconut and reserved coriander to serve.