Much of Iceland's cuisine is based on fish, lamb, and dairy products, with little to no use of herbs or spices. Due to the island's climate, fruits and vegetables are not generally a component of traditional dishes, although the use of greenhouses has made them more common in contemporary food. Þorramatur is a selection of traditional cuisine consisting of many dishes, and is usually consumed around the month of Þorri, which begins on the first Friday after 19 January. Traditional dishes also include skyr (a yoghurt-like cheese), hákarl (cured shark), cured ram, singed sheep heads, and black pudding, Flatkaka (flat bread), dried fish and dark rye bread traditionally baked in the ground in geothermal areas. Puffin is considered a local delicacy that is often prepared through broiling.