test.pl

use v5.14;

my %cache;

package MyDevice;
use Moose;

sub talk_to_device { return 7 }

package MyDummyDevice;
use Moose::Role;

sub init {
    my $self = shift;
    foreach my $method ( $self->meta->get_all_methods ) {
        warn $method->name;
    }
}

around 'talk_to_device' => sub {
    my $orig  = shift;

    if ( ! $cache{talk_to_device} ) {
        # call original function
        warn 'calling original function';

        $cache{talk_to_device} = $orig->(@_);
    }

    return $cache{talk_to_device};
};

package main;
use Moose::Util qw/apply_all_roles/;

my $d = MyDevice->new;
apply_all_roles( $d, 'MyDummyDevice' );

$d->init;