Translation:They sell fruit and vegetables in the supermarket.
You can hear some pronunciations for each dialect here: http://www.focloir.ie/en/dictionary/ei/supermarket. Just click on the C, M, or U to the right of the word "ollmhargadh."
They've added sound now (at least on the version of the question that led me to this thread) but it's approximately 'OLL-war-ga'. (I'm no linguist so this is the best I could do as a layman's phonetic spelling.)
Another site you can try is the Irish language synthesiser at abair.ie - as the name suggests the sound is computer-generated so the quality is lower, but you can slow words or sentences right down and hear them pronounced in the different dialects.