My dictionary tells me that lamb is cordero, it also tells me that mutton is cordero, two butchers in Las Terrenas here tell me that cordero is el hijo de una vaca!!! What do I ask for when I want some mutton chops or indeed any other cut of mutton? Chuletas de oveja?
Mind you when I last lived in the UK it was a hell of a job to find mutton, supermarkets were useless they only sold what they wanted you to buy. Luckily with the help of a proper, old fashioned, butcher I could buy half a sheep from a local abbatoir.