In a pot, heat up Olive Oil (to taste). Add Onion (1) and Ground Beef (500 gram). Cook until beef is browned.
Add Beef Stock (1 cup), Worcestershire Sauce (3 splash), Ketchup (1 dollop), Salt and Pepper (to taste), and Gravy (2 teaspoon). Turn heat down and allow to simmer until mixture starts to thicken.
Transfer mixture to a baking dish. Pat it down until even, and then set aside until cool.
Add Butter (1 tablespoon) and Parmesan Cheese (to taste) to Potato (1 pound). Top the shepherds pie with the potatoes and score with a fork.
Bake at 180 degrees C (350 degrees F) for 20 minutes, or until golden brown on top.