admin.py

from restoran.models import *
from django.contrib import admin

class DishIngredientInline(admin.StackedInline):
    model = Dish.ingredients.through
    extra = 1

    def formfield_for_foreignkey(self, db_field, request=None, **kwargs):
        field = super(DishIngredientInline, self).formfield_for_foreignkey(db_field, request, **kwargs)

        if db_field.name == 'dishingredient':
            if request._obj_ is not None:
                field.queryset = field.queryset.filter(group=request._obj_.group)  
            else:
                field.queryset = field.queryset.none()

        return field

class DishAdmin(admin.ModelAdmin):
    exclude = ['ingredients']	

    def change_view(self, request, obj_id):
        self.inlines=[DishIngredientInline,]
        self.inline_instances = []
 	for inline_class in self.inlines:
            inline_instance = inline_class(self.model, self.admin_site)
            self.inline_instances.append(inline_instance)

        return super(DishAdmin, self).change_view(request, obj_id)
    
    def add_view(self, request):
        self.inlines=[]
        self.inline_instances = []
        return super(DishAdmin, self).add_view(request)

    def get_form(self, request, obj=None, **kwargs):
        request._obj_ = obj

        return super(DishAdmin, self).get_form(request, obj, **kwargs)

class DishGroupAdmin(admin.ModelAdmin):
    pass    

class DishIngredientAdmin(admin.ModelAdmin):
    pass    

admin.site.register(Dish, DishAdmin)
admin.site.register(DishGroup, DishGroupAdmin)
admin.site.register(DishIngredient, DishIngredientAdmin)

models.py

from django.db import models    

class DishGroup(models.Model):
    name=models.CharField(max_length=32)

    def __unicode__(self):
        return self.name

class DishIngredient(models.Model):
    name = models.CharField(max_length=32)
    group = models.ForeignKey(DishGroup)	    

    def __unicode__(self):
        return self.name

class Dish(models.Model):
    name = models.CharField(max_length=32)
    group = models.ForeignKey(DishGroup)	    
    ingredients = models.ManyToManyField(DishIngredient, related_name='dish')	    

    def __unicode__(self):
        return self.name

i to peton?

nice!