Thus my question: what is the easiest way to handle it?

If it's really a simple matter of matching braces then you could indeed use a regex

use Regexp::Common;

my $str = <<CODE;
env {
  foo { bar {} }
}
CODE

print $str =~ /($RE{balanced}{-parens => '{}'})/;

__output__

{
  foo { bar {} }
}
[download]

Check out Re: Graph File Parsing for some regex style parsing, or if you'd prefer to stay away from regexes there's always Text::Balanced.
HTH

_________
broquaint