“Romanesco broccoli or fractal broccoli is an edible flower of the species Brassica oleracea and a variant form of cauliflower. Romanesco broccoli was first documented in Italy (as broccolo romanesco) in the sixteenth century. It is sometimes called broccoflower, but that name is also applied to green-curded cauliflower cultivars. […] The flower has an approximate fractal character, and circles in a logarithmic spiral.”
And you can find it for a couple of euros in any market!