You have to set a key value inside the foreach loop, this would be the key of your current location within the array.
foreach ($array as $key => $value) {
//$key here is your 0/1
foreach ($value as $_key => $_value) {
//the inner pairs
//e.g. $_key = 'chicken' & $_value = 'free'
}
}
You don't need to create an iterator, that has already placed it down a level.