Breaking down the pronunciation:
"Mo": Pronounced as "mo", with a short "o" sound.
"chroí": Pronounced as "KHREE". The "ch" represents a voiceless velar fricative, similar to the sound in the Scottish word "loch". The "r" is trilled.
"istigh": Pronounced as "inshig". The "i" is short, and the "gh" represents a voiced velar fricative, similar to the sound in the Scottish word "loch".
"ann": Pronounced as "onn", with a short "o" sound.