Django: Initialize a container model with child models when a new container is created - e.g. Todo list with default tasks

Question

I'm trying to create a todo list as part of an application that is used to prompt a user what they must complete before the application is assessed. To achieve this I have created a TaskList model and a Task model belonging to a TaskList.

When I create a new TaskList instance (on a new application) I want to prepopulate the list with some default Tasks that will always be present on every new application. I'm relatively new to Django and Python, so I'm just looking for a push in the right direction.

Is there some kind of Django model initialize function I can override on the TaskList to create these default tasks?

Edit: Django Model Fields

class AssessmentTaskList(models.Model):
    title = models.CharField(max_length=140)
    assessment = models.ForeignKey(Assessment, on_delete=models.CASCADE)
    created_on = models.DateTimeField(auto_now_add=True)
    last_modified = models.DateTimeField(auto_now=True)


class Task(models.Model):
    title = models.CharField(max_length=140)
    task_list = models.ForeignKey(AssessmentTaskList, on_delete=models.CASCADE)
    created_on = models.DateTimeField(auto_now_add=True)
    due_date = models.DateField(blank=True, null=True)
    completed = models.BooleanField(default=False)
    completed_date = models.DateField(blank=True, null=True)
    created_by = models.ForeignKey(User, limit_choices_to={
        'groups__name': 'Assessment Staff'}, on_delete=models.SET_NULL, null=True, related_name="applicant_task_created_by")
    system_created = models.BooleanField(default=False)
    note = models.TextField(blank=True, null=True)
    priority = models.PositiveIntegerField(blank=True, null=True)
    created_on = models.DateTimeField(auto_now_add=True)
    last_modified = models.DateTimeField(auto_now=True)
    staff_task = models.BooleanField(default=False)