I tried my home-made tuna and tomato sauce. As I'd got a supply of tinned tomatoes I made the rest of the family a bolognese sauce at the same time. I cook for others like Beethoven wrote music - I have no idea what it tastes like and cannot taste as I go along. It's all pure guess work.
We also obtained a pack of shallots - which are allowed but we very rarely use. It was the last pack in Tesco's and reduced in price to 75p. I feel I could do more with them - can you pickle them like onions?
That was about two weeks ago and I may still be suffering. I had severe tummy-ache for several days following the meal. The Italian restaurants must be using a magic ingredient that counteracts the tomato - perhaps olive oil? This needs to be investigated further. I used about a third of the tin of tomatoes on myself and gave the rest to the others.
So I cannot recommend tuna and tomato as a way of getting tomato into the diet. However in case you have to cook bolognese sauce for the rest of the family when they refuse to share your sardine/mackerel/tuna and cabbage sauce, here is what I did:
brown mince in rapeseed oil;
stir fry some leek, cabbage and shallot in separate frying pan (and that formed the base for my own meal);
add the fried vegetables to browned mince, along with tin of tomato;
add a liberal dose of Italian herbs;
add a little bit of soy sauce;
add two beef stock cubes;
simmer and add some water from the pasta saucepan. If still too runny add a little flour to thicken.
I did not taste this once but they assured me it was delicious - and I did not catch them making faces behind my back.