This is very simple and old recipe. We usually use a kind of plums that grows in area of south Austria, Hungary, Slovenia and Northern Croatia and we call this plum “bistrica”. It is small; the surface is like foggy, and inside is dark yellow and red/brown around stone. It is very sweet so you don’t need too much sugar. It is kind of wild plum so we don’t use any chemistry to prevent diseases. It is very healthy fruit. I named the jam Christmas because we usually start to eat it around Christmas. The ingredients also contribute to the name.