Ah yes was going to say maybe mix a little bit of olive oil into foods??
For the salmon I use fresh. When feeling extravagant and/or lazy
Marks and Spencers do a lovely pack of 2 poached salmon fillets, yum. Easy to break into bits. Or bake some fresh in foil. DH and I have this sometimes so I now chuck another one in for Olly. Enough for him to do another meal the next day
. Have tried tinned salmon in patties and fish cakes but he is not so keen.