01 -
Heat oven to 200°C / 400°F. Cut potatoes into chunks and simmer in water for 15–20 minutes until tender. Drain and mash with butter, milk, half the salt and half the pepper.
02 -
Meanwhile, brown beef in a wide skillet over medium-high heat, breaking up lumps. Drain excess fat, leaving a little to cook the vegetables.
03 -
Add onion and carrots and cook 8–10 minutes until softened. Stir in tomato paste and flour for 1 minute.
04 -
Add broth gradually, stirring. Simmer 10 minutes until the carrots are tender and the sauce thickens. Stir in peas and remaining salt and pepper.
05 -
Transfer filling to a 20 × 25 cm baking dish. Spread mash gently over the top and roughen it with a fork. Bake 20–25 minutes until golden and the filling bubbles; check the center reaches 74°C / 165°F.
06 -
Rest 10 minutes before serving. The filling should be spoonable with thick gravy, not a watery pool under the mash.
07 -
Cool leftovers in shallow containers and refrigerate within two hours for up to three days. Reheat to 74°C / 165°F.