I'm Mexican and we never use `pinche` as Kitchen boy, though some Mexicans would know it also means chef's helper. We always use it as an insult enhancer and can turn almost any curse word into a really rude one:

    pinche pendejo/pendeja = fucking asshole
    pinche puto/puta = fucking faggot/whore
    pinche culero = fucking asshole

When used alone as an adjective it just means something lousy, ugly, something that sucks.

    Esta fiesta esta bien pinche  = This party is really lousy / This party really sucks