sample_models.rb

class Chef < ActiveRecord::Base
 has_many :recipes
 has_many :ingredients, through: :recipes
end

class Recipe < ActiveRecord::Base
 has_many :recipes_ingredients
 has_many :ingredients, through: :recipes_ingredients
end

class Ingredient < ActiveRecord::Base
end

class RecipesIngredient < ActiveRecord::Base
 belongs_to :recipe
 belongs_to :ingredient
end