A kipper is a whole herring, a small, oily fish, that has been split in a butterfly fashion from tail to head along the dorsal ridge, gutted, salted or pickled, and cold-smoked over smouldering wood chips (typically oak). Kippers are traditionally eaten for breakfast in the United Kingdom, Republic of Ireland, and some regions of North America. They are also enjoyed as a high tea or supper treat, most popularly with inland and urban working-class populations before World War II. Kippers are a sustainable fish and are high in Omega 3. They are best from May to September and are pale copper in color. Kippers can be broiled, grilled, or sautéed before serving, and are often enjoyed with butter and lemon and occasionally a poached egg.