そんなの朝飯前よ。

such (about the actions of the listener, or about ideas expressed or understood by the listener); like that; that sort of

indicates possessive; nominalizes verbs and adjectives; substitutes for "ga" in subordinate phrases; (at sentence-end, falling tone) indicates a confident conclusion; (at sentence-end) indicates emotional emphasis; (at sentence-end, rising tone) indicates question

trivial matter; cinch to do; easy as pie; it's a piece of cake

indicates certainty, emphasis, contempt, request, etc.; used when calling out to someone; used to catch one's breath or get someone's attention; yo!