I am really stuck with this grammar point for quite awhile now, and I've asked a fewteachers, but they have being unable to give me a clear logical explanation. I understand the use and structure of a noun modifier using standard masu plain past form, eg たなかさんが かったすしは、......etc etc The sushi that Tanaka bought .....etc Now it's noun modifier with subject ga, masu verb in plain past, modifying the noun, sushi. No worries. However please assist with passive usage in noun modifier, I don't get.
I get that in passive it's the object that's being highlighted, that now forms the subject. And I get direct and indirect passive sentences. No worries.
But what are the rules for using passive to modify a noun and why and when is it prefered over plain masu form?
1.わたしが たべた Pizzaは きのうのばん ともだちに つかいました。 ok all good.
2.たべられた Pizza は おいしかったです。/ or should I use a noun to finish sentence, よくham and pineapple です、
I am not really understanding why No2 in passive, is wrong.
Thank you Shawn Melbourne