Place the salmon in the freezer and freeze for 3 minutes to kill any parasites.
Defrost in the refrigerator. Combine the olives, oregano, shallots, parsley, lemon juice and oil in a mixing bowl.
Just before serving, finely chop the salmon by hand and add it to the olive mixture.
Mound tartar on a plate.
Garnish with lemon wedges and toast.