It doesn't. It returns a single restaurant node. But you proceed to print it and all of its descendants.

To get the desired nodes, you can use the following:

my @nodes =
   $doc->findnodes( '/restaurant/*[ not( self::breakfast_menu ) ]' );
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Maybe you'll find it more useful to simply delete the offending node.

$_->unbindNode() for $doc->findnodes( "/restaurant/breakfast_menu" );
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