More like "mieuso", ę is more like eu than en.

I see you asked a couple of question about pronunciation (including in „Pająk” sentence, which I cannot access at the moment (actually, since a long time ago).

The basic concept is that ą should be nasal o, and ę should be nasal e. But people, in their pursuit for simplier pronunciation, desynchronized some of them. The linked table should help you understand how the pronunciation changes depending on the following letter. (Just copy the whole link manually, because I forgot how to make it display correctly)

https://pl.wiktionary.org/wiki/Aneks:J%C4%99zyk_polski_-wymowa-_zasady#Wymowa_samog.C5.82osek_nosowych