Pick the leaves off a couple of sprigs of rosemary and pound them gently in a mortar and pestle with a little salt.  Add a glug of olive oil and stir, then put to one side.  Fry 2 sliced cloves of garlic in a little olive oil until golden.  Add 1 ¾ cups of good-quality drained and rinsed cannellini beans and continue to sinner gently for 7 minutes.  Season the beans well with salt and pepper and a swig of red wine vinegar, then mash them up using the back of a fork until you have a coarse puree  Smear onto hot toast and spoon rosemary oil over the top.