Grub2 with two EFI disks (Windows 7 + OpenSuSe)

[Mgr. Šimon Tóth]

I just installed my first machine with EFI and because previously the 
best solution was to install Windows to a dedicated disk a did just 
that. But I have no idea how to boot the second disk now from Grub2.

The only howtos I found actually just use a single EFI partition, but I 
have two partitions (one on each disk). I can boot from the BIOS boot 
menu to both Linux and Windows.

I tried some different configurations, but the original simple 
configuration doesn't work:

menuentry "Windows 7" {
        insmod chain
        set root=(hd1)
        chainloader +1
}

I get invalid EFI path error.

So what is the correct configuration for this use case?

--
Mgr. Simon Toth