、。
When it comes to cooking, she's a master.
Literal
Cooking [regarding-にかけては], she [topic-は] master is.
~にかけては is an expression meaning 'when it comes to X,' specifically used when singling out someone's exceptional ability in a particular area. It carries a nuance of 'in that specific field, they stand out.' 名人 (master/expert) is a strong compliment typically reserved for genuine expertise.