I used to work for a humanitarian organisation, that is to say, I was overworked and underpayed. During my time there, I developed what I think is the perfect answer to pushy bosses who put you under time pressure to deliver:

Do you want the job done quickly ? Or do you want the job done well?

(Neutral tone, neutral facial expressions, average voice volume are a must)

I've changed jobs often ever since. To this day, no boss or client has chosen 'quick', questioned the veracity of my statement/question (this obviously means that you must, indeed, deliver quality) or had the nerve to answer 'both'.