01 -
Bring a large pot of salted water to a boil. Add peeled and diced potatoes, and cook until fork-tender, about 10-15 minutes.
02 -
While the potatoes are boiling, heat a large skillet over medium heat. Add pork lard or olive oil. Once hot, sauté the diced onions for 2-3 minutes until soft and fragrant. Add the ground beef, breaking it up as it cooks. Stir in the diced celery and carrots, cooking until the vegetables are tender and the meat is browned.
03 -
Stir in the tomato paste and Worcestershire sauce, ensuring everything is well coated. Let the mixture simmer for 5-10 minutes to meld flavors. For a thicker consistency, stir in a small amount of flour (optional). Remove from heat once done.
04 -
Once the potatoes are cooked, drain them and return to the pot. Mash thoroughly and mix in butter, milk or cream, and your preferred seasonings (salt, pepper, garlic powder) until smooth and creamy.
05 -
Preheat the oven to 200°C (400°F). In a deep 9x9-inch baking dish, layer the meat mixture evenly at the bottom. Spread the mashed potatoes over the meat, smoothing the top. If desired, grate Parmesan cheese over the mashed potatoes before baking.
06 -
Bake in the preheated oven for 20-25 minutes, or until the top is golden brown. Allow to cool for 5-10 minutes before serving.