Prepare fresh seasoning: Finely chop the lemon grass. Peel and grate the ginger. Halve the chilli pepper lengthwise and finely chop.
Finely chop the spring onion and set aside in a small bowl. Grind the peppercorns to taste and mix into the spring onions.
Squeeze the half lime.
Mix the ginger, chilli, lemon grass, 2 tablespoons lime juice, chilli sauce and sesame oil in a bowl.
Add the salmon fillets, cover in the mixture and leave to marinadein the fridge for approx. 1 hour.
Take the salmon fillets out of the marinade and allow it to drip off.
Place in the steamer for approx. 8 –10 minutes, then scatter the peppered spring onions over the top of the fillets with the rest of the lime juice and garnish with whole peppercorns.