I recently listened to a podcast on France Culture's "Hors champ" with Patrick Boucheron, whose pronunciation of "parce que" seems really off. Instead of eliding the "e" in "parce", he actually pronounces the entire word, thus saying "parceee que". I was wondering whether this a high-browed thing, or a regional pronunciation, or has some other class/milieu-related background.
Eliding that e is optional.
Either a formal, a careful or an emphasized pronounciation would be the one you heard: \parsəkə\
A faster one would elide that e: \parskə\
An even faster and likely the most common in casual conversation would drop the r too: \paskə\