# Step-by-Step Directions:
01 - Preheat oven to 400°F.
02 - Boil the potatoes in salted water for 15–20 minutes until fork-tender. Drain well.
03 - Mash the potatoes with butter and milk until smooth and creamy. Season with salt and pepper. Stir in cheddar cheese if using. Set aside.
04 - While potatoes cook, heat olive oil in a large skillet over medium-high heat. Sauté onion and carrots for 3–4 minutes until softened.
05 - Add garlic and cook 1 minute more. Add ground beef or lamb and cook, breaking up with a spoon, until browned and cooked through. Drain excess fat if needed.
06 - Stir in tomato paste, Worcestershire sauce, thyme, rosemary, salt, and pepper. Sprinkle flour over the mixture and stir to coat.
07 - Pour in broth and simmer for 5 minutes until thickened. Add peas and corn, stir, and cook 2–3 minutes more. Adjust seasoning as needed.
08 - Transfer the meat filling to a 9x13-inch baking dish, spreading evenly.
09 - Spoon mashed potatoes over the top and spread smoothly to cover the filling. Use a fork to create ridges for a crispy finish.
10 - Bake for 25–30 minutes, or until the top is golden and the filling is bubbling.
11 - Let rest 5–10 minutes before serving.