Androsace villosa var. jacquemontii

Rock Jasmine. A Himalayan species that was introduced into cultivations recently as 1952. It is easier than you might expect, with tiny silvery grey  leaves, tight buns that form beautiful mats in winter, then transform in summer with inflorescences  on tallish stalks, with new stolons sprouting out the top of the rosette in growth which are another interesting feature. Height 5cm including flowers. Hardy, sun. Great drainage and shingle to protect against winter wet.