Take the famous Bolognese sauce (ragu) for example. Every Italian will tell you that it HAS to be served with Tagliatelli, and the pasta HAS to be added to the sauce before serving. Never the other way round.
Luckily the English were there to improve matters. We looked at it, liked the idea, and altered it. Much better, we thought, to serve the sauce with Spaghetti, and to serve it placed on top. Voila; Spaghetti Bolognese (now an English classic) was born.