。
My cooking repertoire is limited, you know.
Literal
Cooking [possessive-の] repertoire [topic-は] is-limited [explanatory-の].
The sentence-final の is the explanatory particle — it signals the speaker is sharing context, often with a nuance of 'the thing is...' Common in casual speech, particularly (though not exclusively) among female speakers. 限られてる is contracted from 限られている. レパートリー is a loanword from French/English.