Try the following grub.cfg
Make sure to replace --set=root and root=UUID= with the UUID for your system.
The grub.cfg that comes didn't work for me so I made up the following.

Code:
set default="1"
set timeout=30

set menu_color_normal=yellow/blue
set menu_color_highlight=blue/yellow

function load_video {
  insmod efi_gop
  insmod efi_uga
  insmod video_bochs
  insmod video_cirrus
  insmod all_video
}

load_video
set gfxpayload=keep
insmod gzio
insmod part_gpt
insmod ext2

menuentry "Kali 3.7 sdb2" {
  search --fs-uuid --no-floppy --set=root 556feb5a-aa31-4dc0-91ba-1fc416f045c6
  linuxefi /boot/vmlinuz-3.7-trunk-amd64 root=UUID=556feb5a-aa31-4dc0-91ba-1fc416f045c6
  initrdefi /boot/initrd.img-3.7-trunk-amd64
}

menuentry "Windows 7" {
  search --fs-uuid --no-floppy --set=root AAFF-7523
  chainloader (${root})/EFI/Boot/bootx64.efi 
}