Sempervivum tectorum or easier to say let alone remember simply "House Leeks" , Hen & Chicks" or Old Man & Woman". I have heard of House Leeks but not the other two names, how bizarre!
I find them to be a very quirky and odd looking plant, but I am always happy to see them in flower and as they are monocarpic (they die after flowering, thank you google). I never knew this about them though, that they are refrigerant, astringent, diuretic. In rural districts, the bruised leaves of the fresh plant, or its juice, are often applied as a poultice to burns, scalds, contusions, scrofulous ulcers,(don't like the sound of that one) and in inflammatory conditions of the skin generally, giving immediate relief. If the juice be mixed with clarified lard and applied to an inflamed surface, the inflammation is quickly reduced. So there you go... What do you call them out of interest?