This could not be more simple. Go to your local supermarket (eg. Sainsburys). Buy a pizza base. It needs to be one of the fatter style ones, which are always the cheapest, not the fancy thin pizza base you may find in the gourmet section.
Pre-heat the oven to 180 fan bake. Liberally pour olive oil on top of your pizza base, ensuring oil gets into the little indented holes. Chop some rosemary and sprinkle over the top along with sea salt flakes. If you are feeling particularly extravagant, cut some prosciutto into small pieces and sprinkle that over too (as I have done in the picture).
Bake this on an oven tray for about 10 minutes, keeping an eye on it. You want to keep the ‘focaccia’ soft because then it seems more like focaccia, not over-cooked cheap pizza base. Once you are happy with the result, remove it from the oven and cut it into jaunty rectangles, then serve. No one will be any the wiser, but to be honest, it’s such a great shortcut that I tell everyone that it is Sainsburys pizza base and they all express surprise and delight, and I am suitably chuffed, all of which adds to the experience.