This is an easy recipe but one that needs time. It's important to use unhomogenised milk. A sous vide will give you a constant temperature over a long period. You will need a shallow dish - ceramic is ideal.
Preheat your oven to 75ºC or fill your sous vide machine to the minimum level and heat to 75ºC
If you are using the sous vide machine experiment a little. You'll need set your baking dish so that it in the water but not underneath. We placed a pudding basin in first, then the baking dish on top.
Bring the cream to the boil and time for 3 minutes.
Pour the cream into your baking dish and place in the oven or in the sous vide uncovered and leave for at least 12 hours. We left ours in the sous vide machine for 18.
To check whether it is ready, dig in. You'll find the cream has formed a crust and a small amount of liquid remains. (Use this for making scones).
It thickens as it cools. Cover and place in the fridge to cool further. Spread thickly on scones.