Tonkotsu Ramen Broth

Place the trotters and neck bones in a large stockpot and cover with cold water. Bring to a rolling boil over high heat and boil for 5 minutes — the water will turn grey and foul-smelling as impurities purge. Drain, rinse every bone under cold running water, and scrub away any dark clots or membrane. Clean the pot. This step is non-negotiable: skipping it produces a bitter, murky broth.

Return the clean bones to the pot with back fat, shiitake, ginger, scallion, and garlic. Cover with 4 litres of cold water. Bring to a hard, rolling boil and keep it there — the violent agitation is what forces fat and collagen into suspension, turning the broth white. Boil at full blast for 12 hours, adding water as needed to keep bones submerged. The liquid level will drop by nearly half. Partially cover to reduce splatter but maintain the boil.

During the 12-hour boil, skim away any thick grey foam that collects at the edges in the first hour. After that, resist the urge to skim — the white turbidity is collagen and emulsified fat that you want in the final bowl. Only remove solid flotsam (bone chips, mushroom stems). Check the pot every 2 hours.

Set a fine-mesh strainer lined with cheesecloth over a clean pot. Ladle the broth through — do not pour, as the bones shifting will cloud the liquid further. Discard solids. Season the finished broth with salt, tasting after each addition; it should taste deeply savoury on its own but mild enough to accommodate tare (seasoning sauce) and toppings. Cool and refrigerate if not using immediately — the broth will set into a firm ivory jelly.