With their attractive brightly coloured, smooth, shiny skins, chillies range from mildly hot to scorchingly fiery. Red and green chillies are widely available although yellow and orange varieties can also be bought. They come in a range of different varieties and shapes, ranging from long and slender to round and bulbous. Popular as an everyday ingredient in a variety of cuisines, including Thai, Indian, Mexican and Chinese, chilies can add just a subtle flavour or a real kick to a wide selection of savory dishes. As a general rule the smaller the chili the hotter it is but the colour is no guide to heat. The heat of the chili comes from capsaicin, a type of oil, which is concentrated in the seeds and the white pith that surrounds the seeds, although it is present in the flesh too. When buying, choose firm chilies with a shiny unblemished skin.