Try this "Classic Shepherd's Pie with Crispy Cheddar Topping" from The Food Charlatan - beef part of this recipe has onion, carrots and peas, and is seasoned with beef broth, Worcestershire sauce, and Better Than Bouillon paste.
How to Cook Gordon Ramsay's Amazing English Shepherd Pie. I used 2 sweet potatoes, 1 egg yolk and 2 TBS heavy cream for the potato topping. I also substituted 12 oz beer in place of the stock and wine and added chopped kale. I did not use Parmesan cheese.