active admin saving selection from collection_select and passing to controller

hi i am using active admin for my app i have a partial with a drop down
list where the menu and recipe are populated this page is to group the
recipe in a menu _menu_recipe.html.erb

<%= semantic_form_for [:admin, @menu_recipe] do |f| %>

<p>
<%= f.collection_select :recipe_id,
  Recipe.all,:id,:name,:prompt => true%>
</p>
<p>
<%= f.collection_select :menu_id,
  Menu.all,:id,:name,:prompt => true%>
</p>
<%= f.buttons :commit %>
<%end%>
when ever i try to catch the and create or group it, it comes with a
Couldn't find Recipe without an ID error

my active admin controller which i override is

ActiveAdmin.register MenuRecipe do
    menu :parent => "Manage Package"

   form :partial => "menu_recipe"

    controller do
      def new
        new! do |format|
          @menu_recipe = MenuRecipe.new
        end
      end

      def create
        create! do |format|
          recipe = Recipe.find(params[:recipe_id])
          menu = Menu.find(params[:menu_id])
          @menu_recipe = @menu.add_recipe(menu.id)

          if @menu_recipe.save
            redirect_to {admin_menu_recipe_url}
          end
        end
      end
    end

end
i cant seems to get the current menu and recipe that i group