For chashu, combine all ingredients in a large saucepan. Cover with cold water and bring to the boil. Reduce heat to low and braise pork, covered, until tender (2-2½ hours). Cool in braising liquid, then refrigerate to chill. Cut pork into 5mm-thick slices.

For black garlic miso bomb, combine nori, sesame seeds and dashi powder in a spice grinder and process until finely ground. Halve black garlic horizontally and squeeze it from its skins into a bowl. Stir in miso paste, ground nori mixture and white pepper. Roll into 4 balls and set aside until required.

For tsukemen broth, heat oil in a large saucepan over high heat. Add pork mince and cook, breaking up lumps with a wooden spoon, until deeply browned (10-12 minutes). Reduce heat to medium. Add onion, apple, garlic and ginger and cook, stirring, until lightly caramelised (4-5 minutes). Add pork stock and bring to the boil. Reduce heat to medium-high and simmer until reduced to 1 litre (25-30 minutes). Remove from heat and strain broth through a fine sieve into a clean saucepan, pressing down on solids to extract maximum flavour. Whisk through shiitake-bonito powder to combine.

Heat oil in a large frying pan over medium-high heat. Add pork belly slices and cook, turning once, until lightly charred and warmed through (2-3 minutes). Remove from pan.

Meanwhile, cook noodles in a large saucepan of boiling water until cooked but still firm (1-2 minutes). Drain and rinse under cold running water.

Bring broth to a gentle simmer. Divide among small serving bowls; add a black garlic miso bomb to each bowl and whisk to combine. Drizzle with sesame oil. Serve hot soup with noodles, pork chashu, Chinese broccoli, ajitama, nori and spring onion on the side.