There a plenty of Panna Cotta recipes. I've tryed several, and here is my optimal mix.
You will need: 500 ml Cream (Schlagsahne, сливки), 100-150 ml Milk, 100 (or even less) sugar, gelatin.
Mix cream and milk and cook till it gets hot. Add sugar.. try..add, try... till it the optimal sweetness for you. Then add gelatin and let it melt. Then let it cool down, put into forms and in the frige. You can of course serve it in forms, also you can put any sauce you like on top, decorate with berries. My favourite idea is as on the picture. Our family Cook Mar Munkittrick sold to my this idea: When your mix it already in a form, put a short glass there. Then after it's ready you can fill it with any nice sauce. My favourite is just blended berries.