Complex sentence: The Italian version of mirepoix is called "soffritto" (not to be confused with the Spanish "sofrito"), a base of finely chopped parsley and onion sauted in lard, but most modern cooks substitute olive oil or butter.
Split into simpler sentences: The Italian version of mirepoix is called "soffritto" (not to be confused with the Spanish "sofrito"). Traditional ingredients were lard and finely chopped parsley and onion, but modern cooks substitute olive oil or butter.