Toast the cumin seeds, fennel seeds, Sichuan peppercorns, and black peppercorns in a dry pan until fragrant.
Grind to a fine powder using a mortar and pestle or spice grinder.
Stir in the sesame seeds (semi crushed for texture), chilli powder, salt, sugar, MSG, citric acid, crushed chillies, and five-spice powder.
Store in an airtight container in the fridge. Consume within 2 weeks.
Trim off excess fat on the lamb and place in a large pot with ginger, sichuan peppercorn, green onions and shaoxing wine.
Top with water and bring to a boil on medium heat.
Once simmering reduce the heat to low and cook for 90 minutes, skimming the scum as needed.
Transfer the ribs to a wire rack, pat dry, and season generously with the spice mix.
Chill for at least 4 hours, or overnight for best flavour.
Grill over high heat: barbecue, hot cast iron, or charcoal coals until charred and smoky.
Garnish with red onion and coriander.