1) In a bowl, mix all the ingredients except salmon.
2) Take a non metallic dish and add a quarter of the mixture over its base.
3) Place the salmon fillet, skin side down.
4) Add half the mixture over the salmon, sandwich it with second fillet, skin side up.
5) Using a greaseproof paper and cover. Using a 2 lb (900 g) weight, weigh down for two days, turn occasionally.
6) Serve thinly sliced with lemon wedges and brown bread.