If there’s one thing Argentinians love more than a juicy steak it’s the uber sweet dulce de leche , an intensely creamy, thick caramel sauce. You can buy it ready made, but you just can’t beat the flavour of homemade. The secret to success is to cook it really, really slowly, so you need to commit yourself to 3 or 4 patient hours or more in the kitchen. If you do it too quickly, you risk the milk proteins curdling, leaving you with a gritty end result. This recipe makes more dulce de leche than you need for the ice cream, but it will keep in the fridge for at least a month, and is fabulous spread on to hot waffles or toast.
Note: you will need to begin this recipe the day before you want to eat, as the dulce de leche needs to be chilled thoroughly before turning into ice cream; the ice cream itself takes at least another 5–6 hours to freeze.
Pour about 500ml of the milk into a large saucepan or stockpot and set it over a medium heat. Add the sugar and stir continuously until it has dissolved. Then pour in the rest of the milk and add the bicarbonate of soda, stirring until completely mixed.
Reduce the heat to an absolute minimum and leave to caramelise for about 3½ hours. Give the mixture a stir from time to time, about every 15 minutes or so. You are looking to keep it from boiling, just at a bare simmer, or you will be in danger of a grainy, rather than smooth, result.
Turn off the heat when the dulce de leche is a deep caramel bronze and about the consistency of thick double cream. It will thicken to a spreadable consistency once cold. If in doubt, put a little on a spoon and chill quickly in the fridge to check what it will be like when cold. This recipe should yield around 500–600ml dulce de leche . Pour 400ml into a jug and set aside to go cold, then chill thoroughly. This will be the base for the ice cream. Store the rest in a jar or covered bowl in the fridge to be used as desired.
When you are ready to make the ice cream, pour the cream into a large bowl and add the vanilla extract. Whisk to firm peaks by hand or using an electric whisk, then take a large metal spoon and fold through the measured chilled dulce de leche
Pour into a plastic tub, cover and put in the freezer for at least 5–6 hours, or overnight, until set. To serve, remove from the freezer and allow to sit at room temperature for 30 minutes before scooping into cups or cones.