Interesting to note that the term ‘Denver Omlette’ was recorded to be first used in print in exactly the same year as ‘black power’, ‘bruschetta’, ‘cash-flow' and ‘Doppler radar’.

My thanks to @jack for the link to the Meriam Webster Site where you can learn this … then again - they also record ‘pasties' in that same year - but meanwhile here The Dictionary of Medical Vocabulary in English, 1375–1550 specifically references ‘pasties’.

SO, either the site is American centric - which of course being MW - it likely is ) OR maybe they are referring to different pasties - which can be learnt about here.