package Foo;
use warnings;
use strict;

sub new {
    return bless {}, $_[0];
}
sub blah {
    my ($self, $args) = @_;

    my $method = 'process';

    my $updated = $self->$method($args);

    return $updated;
}
sub process {
    my ($self, $args) = @_;

    my @updated;

    push @updated, $_ * 2 for @$args;
    
    return \@updated;
}

package main;

my $obj = Foo->new;

my $method = 'blah';
my $args = [qw(1 2 3)];

my $return = $obj->$method($args);

print "$_\n" for @$return;