"-어/아/여 보지 그러세요." "-지 그러세요" is used to show talker wants to suggest listener something carefully. (김치를) 한번 먹어 보세요. please just try to eat 김치 once. (김치를) 한번 먹어 보지 그러세요. (As I see,) It seems to be good for you, so please try to eat 김치 once.