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
Marjani	-	Eastern African, Swahili
Klaus	KLOWS (German, Finnish)	German, Danish, Norwegian, Finnish
Huw	-	Welsh
Kalyna	kah-LI-nah	Ukrainian (Rare)
Anisim	-	Russian
Robin	['rɔbin]