Put the pan on the stove over medium heat. And then - don't touch it! This is the hardest part) Sugar will start to melt after a while. DON'T INTERFERE! Sometimes the pan can only be swung slightly from side to side.
At the same time, put the cream on the stove. Put it on low heat. They need to be brought to a boil by the time all 200 g of sugar has melted.
When the sugar has melted, add the next portion. DON'T INTERFERE! Just wait and admire) But do not go far from the stove, so as not to miss the moment when the sugar melts.
If suddenly the sugar has crystallized, it is better to throw away what happened and do it again... Otherwise, you risk wasting cream and butter...