Flake the salmon from the tin into either large pieces, draining it well. Heat a cupful of aspic until just liquid enough to pour, then arrange the salmon in layers in a wet mould, interspersing it with thinly sliced lemon and halved olives. Pour the aspic over it and set aside to chill and harden. Turn out on an icy cold plate and arrange thin slices of cucumber (previously crisped in ice water) about it, masking them with a stiff mayonnaise.
Heat a cupful of aspic