In a large, heavy-bottomed pot, combine the heavy cream and whole milk.
Heat the mixture over medium heat until it reaches a simmer. Do not let it boil. Stir occasionally to prevent scorching.
Reduce the heat to low and let the mixture simmer gently for about 2-3 hours, stirring occasionally. During this time, a thick layer of cream will form on the surface.
After 2-3 hours, remove the pot from the heat and allow it to cool to room temperature. As it cools, the thick cream layer (kajmak) will solidify.
Once cooled, use a slotted spoon or spatula to carefully skim off the thick cream layer and transfer it to a separate bowl.
Sprinkle the skimmed kajmak with salt and mix gently.
Transfer the kajmak to an airtight container and refrigerate for at least 24 hours before serving to allow the flavors to develop.
Enjoy your meal!