Prepare all of the seafood beginning with opening the oysters in a sieve more than a bowl to capture the juices (see video technique).
Trim and slice the salmon into 6 equal-size square chunks. If the scallops are large, cut them by 50 % lengthways. Peel and devein the prawns when necessary.
Place the strained oyster juice and fish stock in a shallow saucepan and provide to a simmer.
First add the salmon and poach for 1 min.
Add the prawns and oysters (if using large ones) and poach for 1 min more.
Add the scallops and poach for 1 min more, start being active .
The oysters (if small) and simmer everything for just a final min until just cooked.
