1. Preheat your oven to 400°F (200°C). This temperature helps develop a golden crust on the mashed potato topping without drying it out.
2. Start by peeling and chopping your potatoes. Place them in a pot of cold, salted water and bring to a boil. Cook for about 15-20 minutes or until tender when pierced with a fork.
3. While the potatoes cook, heat a large skillet over medium heat. Add a splash of oil and sauté the chopped onion and carrots for 5 minutes or until softened.
4. Add the minced garlic and cook for another minute until fragrant—this is when the aroma fills the kitchen, reminding me of those family dinners where everyone gathered just from the smell.
5. Add the ground beef or lamb to the skillet. Break it up with a wooden spoon and cook until browned, about 7-8 minutes. Drain excess fat if needed to keep things from getting greasy.
6. Sprinkle the flour over the meat mixture and stir well to coat. This step helps thicken the filling as it cooks.
7. Mix in the tomato paste, Worcestershire sauce, and pour in the beef broth. Stir to combine, then let the mixture simmer for 10 minutes. You’ll notice it thicken and become rich and saucy—this is where the magic happens.
8. Stir in the frozen peas, season with salt and pepper, and cook for another 2 minutes. The peas add a pop of color and sweetness, a small but meaningful detail that elevates the dish.
9. Drain the potatoes and mash them with butter and milk until creamy and smooth. Season with salt and pepper to taste. When I make mashed potatoes, I like to leave a few lumps here and there—it adds a rustic texture that feels more homemade.
10. Transfer the meat filling to a baking dish, spreading it out evenly. Dollop the mashed potatoes on top and gently spread them with a spatula or fork. Create some texture on the surface by swirling or making peaks with the fork—this helps the topping brown nicely.
11. Bake in the preheated oven for 20-25 minutes, or until the mashed potatoes are golden and the filling is bubbling around the edges.
12. Remove from the oven and let it rest for 5 minutes before serving. This pause lets everything settle, making it easier to serve and enjoy.

Remember, cooking is about trial and error—my early kitchen mishaps taught me that a well-timed rest can make or break a dish.