Prepare the Mashed Potatoes
Place the cubed potatoes in a medium saucepan and cover with water. Add a pinch of salt.
Bring to a boil, reduce heat, and simmer until the potatoes are fork-tender (about 15 minutes).
Drain and mash the potatoes with butter and milk until smooth. Add salt to taste. Set aside.
Cook the Meat Filling
Preheat your oven to 400°F (200°C).
Heat olive oil in a large skillet over medium heat. Add the diced onion and garlic, sautéing until fragrant and translucent.
Add the ground meat, breaking it up with a spoon, and cook until browned. Drain excess fat if needed.
Stir in the diced carrots, peas, and corn, cooking for 3–4 minutes.
Add tomato paste, Worcestershire sauce, thyme, and broth. Stir well and let simmer until the liquid reduces slightly, creating a thick, flavorful filling. Season with salt and pepper to taste.
Assemble the Shepherd’s Pie
Transfer the meat mixture to a baking dish, spreading it out evenly.
Spoon the mashed potatoes over the meat layer, smoothing them with a spatula. For extra flair, create swirls or peaks in the potatoes using the back of a spoon.
(Optional) Sprinkle shredded cheddar cheese over the mashed potatoes for a cheesy crust.
Bake to Perfection
Place the baking dish in the preheated oven and bake for 20–25 minutes, or until the mashed potato topping is golden and slightly crispy.
Remove from the oven and let cool for 5 minutes before serving.