1.

Preheat the oven to 350˚F.

2.

Put the potatoes in a medium saucepan, cover with water and bring to a simmer; cook until fork-tender.

3.

Drizzle some oil into a large skillet, set it over medium-high heat and cook the beef and onion for 4-5 minutes, breaking the meat up with a spoon until it’s no longer pink inside.

4.

Sprinkle the flour over the meat and stir to coat.

5.

Add the stock, tomato paste and Worcestershire and bring to a simmer, stirring often, until the mixture thickens.

6.

Stir in the carrots and peas, season with salt and pepper and pour into a baking dish.

7.

Drain the potatoes and return them to the pot with the butter and milk. Roughly mash, then spread over the beef mixture.

8.

Place on a baking sheet (to catch any drips) and bake for 30 minutes, or until heated through and bubbly.