haven't read the whole thread but feel compelled to make a couple of points.
the reason pasta tuna bake doesn't work is that most, if not all, pasta fish dishes should NOT have any cheese of any type in them. Most italians would probably refuse to even taste such a combination, let alone eat it.
and the lemon, parmesan pasta dish. this is indeed a popular, authentic dish and I had it less than 2 weeks ago, cooked by my BF at her place in Italy. it's a really basic recipe and DELICIOUS
there are loads of recipes but this is the easiest, simplest and tastiest
for four ppl
2 lemons
olive oil
sea salt
parsley
parmesan
put water to cook pasta on to boil, salt it and add one of the lemons cut in half - don't squeeze or anything, just put in the water
grate plenty of good fresh parmesan or grana padana but is must be FRESHLY GRATED
grate the zest of the other lemon into the parmesan.
when the pasta is 'al dente', drain it, take the lemons out, return pasta to pan
add the parmesan and grated lemon zest to the pasta - mix well
serve with a sprinkling of very finely chopped parsley and a little splash of olive oil.
Go on, try it, you'll be pleasantly surprised.....
it's healthy, good for you and cheap