Combine the sugar and cinnamon in a shallow dish and set aside.

Preheat Convection to 180°C.

To make the churros, mix together flour and salt in a bowl. Add oil and boiling water and stir until combined and a thick, sticky batter. Transfer to a piping bag fitted with a large star tip nozzle.

Line the enamel tray with non-stick baking paper. Pipe out thick 8cm strips of churro batter onto the prepared tray, using a knife to release each piece from the piping tip, if needed. Bake for 20 minutes.

Place butter in a shallow bowl, cover and microwave for 30 seconds at 600W.

Dip the churros in the butter, then roll in the cinnamon sugar.

To make the chocolate dipping sauce, place the chocolate in a microwave safe dish. Microwave chocolate for 30 seconds, stir, and microwave for a further 2 rounds of 30 seconds and stir. Serve straight away with churros.