Errors when trying to setup factories using a has many association

I have a Restaurant model that has_many Dishes. The problems occur when trying to create this association in my restaurant factory. Following some related posts here on SO I created the necessary association between the two and a before_save callback to add a dish to the restaurant. Unfortunately when I run my tests I get:

 NoMethodError:
   undefined method `create_dish' for FactoryGirl:Module

What do I need to fix in order for my tests to run correctly?

Restaurants.rb

FactoryGirl.define do
  factory :restaurant do
    association :dish, factory: :dish

    name "Dinosaur Bar-B-Que"
    address "700 W 125th St, New York, NY 10027"
  end

  after(:create) do |restaurant|
        FactoryGirl.create_dish(:dish, 1, restaurant: restaurant)
  end
 end

Dishes.rb

FactoryGirl.define do
  factory :dish do
    name "Bar-B-Que Pork Ribs"
    description "our st. louis ribs are dry rubbed and slow pit-smoked, then lightly glazed with our original bbq sauce."
  end  
end