YOU SAID:
I was cooking chicken today
INTO JAPANESE
今日は鶏肉を焼いていました
BACK INTO ENGLISH
I cooked chicken today.
INTO JAPANESE
今日は鶏肉を焼きました。
BACK INTO ENGLISH
I grilled chicken today.
INTO JAPANESE
今日はチキンを焼きました。
BACK INTO ENGLISH
I grilled chicken today.
That didn't even make that much sense in English.