Using a frying pan with no oil, quickly dry roast star anise, sichuan peppercorns, and coriander seeds until fragrant, approx 1 minute. Remove and grind down to a powder. Set aside.
Season beef with salt. Heat some vegetable oil in a large stewing pot. Add beef shanks to the hot pot and brown all sides, about 3 minutes per side. Remove browned shanks and set aside.
Using the same pot, fry onion, celery, carrot, and garlic until soft (season with a little salt during frying).
Add another splash of oil to the pan along with the spice mix and chilli flakes. Cook a few minutes until fragrant, stirring around so spices don't stick or burn.
Next, add gochujang paste. Cook for 1 minute.
Add stock, honey, soy, apple cider vinegar and grated potato to the pot, and combine well. Now place the beef shanks into the sauce, bring to a boil, place a lid on top, and simmer for 3 hours.
Cook rice or noodles, according to packet instructions.
Coriander garnish: Combine spring onions, coriander, lime in a small bowl.
The meat should have fallen off the bone by now. To divide into small pieces use two forks to shred. Make sure all the bone marrow has melted away from inside the bones and into the sauce. If not use a knife to remove it and stir through. Discard bones.
Serve the beef stew on top of rice or mix into noodles. Squeeze over lime and garnish with coriander and spring onion. Sprinkle with sesame seeds if you have them.