Sounds like Moroccan food = aklu maghribi, but a couple of examples back, i think it was "good food", and it was aklun maghribi. Both are adjectival phrases, so why the difference between aklu and aklun?
Yes, the audio is wrong in fact. It should be (aklun), not (aklu) here.
The -un vowel is called Tanwin or Nunation. You can consider it as a marker for indefinite nouns (and adjectives), somehow similar to the a/an in English. Since the sentence above is indefinite (the word for food أكل is not defined with AL) then it should be (aklun) أكْلٌ