#!/usr/bin/perl -w
use strict;

my @values = ('CHOCOLATE CHIP', 'PLATINUM', 'GASOLINE', 'GOLD');

my %hash = (
    'COOKIE' => ['CHOCOLATE CHIP', 'PEANUT BUTTER'],
    'METAL'  => ['SILVER', 'GOLD', 'PLATINUM'],
    );    

THING: foreach my $thing (@values)
{
   foreach my $type (keys %hash)
   {
      if (grep{$_ eq $thing}@{$hash{$type}} )
      {
         print "$thing is a $type\n";
         next THING;
      }
   } 
   print "$thing is UNKOWN\n";
}

__END__
CHOCOLATE CHIP is a COOKIE
PLATINUM is a METAL
GASOLINE is UNKOWN
GOLD is a METAL