Heat the milk and cream gently. Split the vanilla bean in half and scrape out the seeds with the dull (non-cutting) side of a paring knife. In a medium saucepan, add the vanilla beans, pod, milk, and cream. Cook over low heat until it begins to simmer and bubbles appear around the edge of the saucepan. Do not boil the milk. Turn off the heat.
Whisk eggs and sugar. Place the yolks and 100g/½ cup sugar in a medium-sized mixing bowl and whisk until thickened and pale.
Combine the two mixtures & temper the egg yolks. Remove the vanilla pod from the milk mixture and discard. While whisking the yolks continuously, pour a cupful of the milk mixture in a thin stream into the yolks. Then slowly pour in the remainder. TIP: Place the bowl on a tea towel to stop it from sliding around. Whisk until thoroughly combined.
Thicken the custard. Pour the mixture back into the saucepan and return to low heat on the stovetop. While continuously whisking, heat the custard until it thickens. Test by coating the back of a spoon and running your finger through it—if the pass stays, the custard is sufficiently thickened. If it joins, continue heating on the stovetop.
Sieve, cool, and refrigerate. Pour the custard through a sieve set over a bowl, cover with plastic wrap touching the surface to prevent a skin from forming. Place in the fridge and leave to cool down for at least two hours—or until cool and thickened. It’s best to leave it overnight for super creamy ice cream.
Make the caramel brittle. Prepare a baking sheet with parchment paper. Add the sugar to a heavy-based saucepan and heat on medium to low heat until the sugar has dissolved and turned golden brown. During this process, swirl the sugar around the pan to help the sugar dissolve evenly. Working quickly but carefully, pour the caramel onto the prepared baking sheet and smooth it out with an offset spatula. It hardens quickly, so you need to be speedy. Leave to cool and set for ten minutes, then chop into various sized pieces.