Start with a Rasbian light version.
Install chromium and x-server
sudo apt-get install xserver-xorg
sudo apt-get install xinit
If you now start chromium-browser it will show the following error:
Gtk-WARNING cannot open display
this is because you have to start it with xinit:
Chromium will start, but you will need a minimal window manager.
Now you need a shell script to start your chromium
Insert the following lines, Exit with ctrl+x, Y and Enter.
matchbox-window-Manager -use_cursor no&
Start it now with:
Add Chromium options as you like. E.g. –Kiosk –allow-running-insecure-content plus your URL