be in (one's) element

To be doing something that one is very comfortable with or proficient in. My mother is in her element in the kitchen and can make just about any dish.

Common Names:

Name	Pronounced	Usage
Meagan	MEG-ən	English
Ciera	see-ER-ə	English (Modern)
Linn	LIN	Swedish, Norwegian
Dominica	-	English (Rare), Late Roman
Elizabeth	i-LIZ-ə-bəth (English)	English, Biblical
Connell	['kɔnəl]