YOU SAID:

He was eating a sandwich and rice not omurice or bread

INTO JAPANESE

彼はオムライスやパンではなくサンドイッチとご飯を食べていました

BACK INTO ENGLISH

He was eating sandwiches and rice instead of omelet rice and bread

INTO JAPANESE

彼はオムライスとパンの代わりにサンドイッチとご飯を食べていました

BACK INTO ENGLISH

He was eating sandwiches and rice instead of omelet rice and bread