Begin by bringing a large pot of salted water to a boil. Carefully add the peeled and cubed potatoes, then boil for 15–20 minutes until fork-tender. Drain the potatoes and return them to the warm pot. Add unsalted butter and whole milk or heavy cream, then mash until smooth and creamy. Season with salt to taste, then set aside while you prepare the filling.

In a large skillet, heat a splash of olive oil over medium heat. Once hot, add the chopped medium onion and minced garlic cloves, sautéing for about 5 minutes until they turn translucent. Next, introduce the ground lamb or beef to the pan, breaking it up as it browns evenly for about 6–8 minutes. Stir in the diced carrots, frozen peas, and corn, cooking until they soften, about 3 minutes.

Stir in tomato paste, beef or chicken broth, Worcestershire sauce, dried thyme, salt, and pepper into the skillet. Let the mixture simmer on low heat, stirring occasionally, until it thickens, about 10 minutes.

Once your filling is ready, preheat your oven to 400°F (200°C). Transfer the savory meat filling into a baking dish, spreading it evenly. Now, gently layer the prepared mashed potatoes on top.

Place the assembled dish in the preheated oven and bake for 20–25 minutes. Keep an eye on it as the top develops a lovely golden crust. Once the edges begin bubbling and the top is slightly crispy, it’s ready to come out.

Scoop generous portions of your Famous Homemade Shepherd's Pie onto plates, serving with a side of fresh salad or steamed vegetables if desired.