New controller pattern

recipes_controller.rb

class RecipesController < ApplicationController
  ...
  
  def new
    @recipe = flash[:recipe] || Recipe.new
  end
  
  def create
    @recipe = Recipe.new(params[:recipe])
    
    if @recipe.save
      flash[:notice] = 'Recipe was successfully created.'
      redirect_to recipes_path
    else
      flash[:recipe] = @recipe
      redirect_to new_recipe_path
    end
  end
  
  ...
end