The large shape was cut from a foam sheet (which you can buy from Regal craft cards) using a nesting die and secured to an acrylic block with a little bit of double sided tape so that it could be used as a stamp.
You can just stamp in the ordinary way, in which case the result is a solid image of the diecut, but in this instance, for the bottom layer, the flower was inked up, and then an uninked (Darkroom Door) background stamp was pressed onto it. Instead of stamping the leaf pattern, it removed the pink ink from the diecut, which was then stamped onto the white background circle - patterned stamping!
The image of the inked diecut remains on the background stamp, so if you work quickly you can stamp a "negative" patterned image too!
I've made it sound a lot more complicated than it is. You can use any solid stamp coupled with a relatively densely patterned one. This technique appears under many different headings - often Kiss-stamping if you want to search for more info.
The base card is one of Regal Craft Cards newer cards - Stonewash (PL27), which despite its name is a very on-trend shade of grey.