django - Mapping a different field OneToOneField in a ModelForm

Question

I have two django models related with a OneToOneField. I'll show the relevant fields:

class User(AbstractBaseUser, PermissionsMixin):
    email = models.EmailField(unique=True, db_index=True)

And

class PasswordRecovery(models.Model):
    user = models.OneToOneField(User, primary_key=True)
    token = models.CharField(default=utils.make_token)
    password = models.CharField(max_length=128)

Then I have a form for the PasswordRecovery model

class PasswordRecoveryForm(forms.ModelForm):
    password_check = forms.CharField(max_length=128)
    class Meta:
        model = PasswordRecovery
        fields = ('user', 'password', 'password_check')

A few details are omitted here. Tell me if you think they are relevant.

The problem is that the user field shows as a 'select' element and I would like it to be an email field. Instead of being able to chose a user from a lista I want it instead to required the email to be typed.

How can I do this?

Thanks in advance