1. In a small saucepan, bring the milk, butter and sugar to boil and keep boiling for 1 minute. Take off the heat and, using a wooden spoon, beat in the flour and salt.
2. Once all the flour is combined, put the saucepan back on a low heat and continue to stir firmly for 1 minute. Transfer the dough into a bowl and stir for 1 minute to cool it down.
3. Mix 1 whole egg and the yolk from another and slowly add to the dough whilst continuing to beat with a wooden spoon. Place a star nozzle in a piping bag and transfer the mix.
4. Melt the chocolate over a bainmarie or in a microwave. Bring the cream to the boil in a pan and slowly stir the chocolate until combined.
5. Heat a pan of vegetable oil to 170ºC (if you don’t have a thermometer, drop in a cube of bread – it will turn golden after 20 seconds at 170ºC). Pipe the churros mix into the oil, using scissors to cut 5cm lenghts. Once they are golden, transfer to a cooling rack. Mix together the sugar and cinnamon and coat the churros. Serve warm with the chocolate sauce for dipping and some chopped nuts (optional).