Place marinade ingredients into a jar or bowl and whisk for 30 seconds. Pour marinade into a resealable bag, then add the fish fillets.
Carefully massage the fish until the fillets are completely covered in marinade. Remove air from bag then seal and place in fridge to marinate overnight (or a few hours if in a rush).
Remove fillets from the marinade and discard the marinade.
Sprinkle the sugar and chillies on top of fillets then place on a baking paper lined ovenproof tray and then place in preheated oven at 200°C.
Cook the fillets for 8-10 mins, then place under a grill until golden.
Meanwhile prepare the asparagus, trim the woody ends rinse and set aside. In a medium skillet melt the butter and once beginning to bubble add the lemon zest, some salt and pepper then toss the asparagus until just cooked.
To serve add some asparagus to each plate and top with a golden fillet of toothfish. Sprinkle with extra chilli and micro herbs to finish.