sub hpairs (\%) {
    my $href = shift;
    map[ each %$href ], 1 .. keys %$href;
}

my %salary = (
    boss      => 1_000,
    secretary => 300,
    admin     => 600,
    janitor   => 150,
);

print for map { 
    "$_->[0] earns $_->[1]" 
} sort { 
    $a->[1] <=> $b->[1] 
} grep { 
    $_->[1] > 500 
} hpairs %salary;

__END__
admin earns 600
boss earns 1000