Prepare the Mashed Potatoes: Place peeled and chopped potatoes into a medium saucepan, covering them with water. Bring to a boil and cook until tender, about 15–20 minutes. Drain, add butter and milk, mash until smooth, and season with salt and pepper.

Cook the Meat Filling: In a large skillet, heat olive oil over medium heat. Sauté onion and garlic for 2–3 minutes. Add ground meat, cook until browned, about 5–7 minutes. Stir in carrots and peas, then add tomato paste, beef broth, Worcestershire sauce, thyme, salt, and pepper. Simmer until thickened, about 5–7 minutes.

Assemble the Shepherd’s Pie: Preheat oven to 375°F (190°C). Spread meat filling in a baking dish, then spoon mashed potatoes on top, creating patterns with a fork.

Bake the Pie: Bake in preheated oven for 20–25 minutes or until potato topping is golden. Add shredded cheese during the last 2–3 minutes.

Add Final Decorations: Let the pie cool for 5 minutes, then add black olives and drizzle ketchup or sriracha for decoration. Serve hot.