YOU SAID:

I just prepared my lunch

INTO JAPANESE

昼食を用意したばかりだ

BACK INTO ENGLISH

We just had lunch.

INTO JAPANESE

ちょうど昼食をとったところです。

BACK INTO ENGLISH

I just had lunch.

INTO JAPANESE

いまお昼を食べたとこ。

BACK INTO ENGLISH

I have just eaten lunch.

INTO JAPANESE

いまお昼を食べたとこ。

BACK INTO ENGLISH

I have just eaten lunch.