all those receipes assume you know how to cook in general - people not cooking on a regular basis will always take longer that 15 minutes to prep meals.
my tip: cook a small amount once even if it takes a while; if you are fine with the result, cook a larger amount that you can freeze or store for future meals, reducing your total cooking time far below those 15 minutes. dont just do large amount first - you will profit from having done the receipe before and achieve a better tasting meal the second time.