Diners were tucking into their upmarket Indian lunch when the Ice agents slid through the restaurant’s back fence. Armed with stun guns and clad in stab vests, the 11-strong unit blocked off every entrance before moving in on their target: Mandira’s Kitchen. This wasn’t a scene from California or Texas. It happened near Guildford, England, among the rolling Surrey Hills.Before the Home Office’s immigration compliance and enforcement (Ice) officers stormed the restaurant in September, they came up with a codeword in the event they were attacked with any weapons that might be at hand in a kitchen. What they found…