Prepare the mashed potatoes ahead of time. Place the potatoes in a small pot and cover with cold water, season with salt. Bring to a boil and cook for 10-15 minutes until soft. Drain, return to the pot and add the butter and milk. Mash together until smooth-ish and set aside. Taste for salt and season if needed.

Heat a heavy saucepan or pan over medium-high heat and add a splash of olive oil. Add the pre-made beef, cinnamon, thyme and salt and stir through. Add the frozen peas and corn, no need to thaw out. Stir for a minute and then add the tomato sauce and water. Stir and cook together for a couple of minutes.

In the meantime, whisk the flour and a little water in a bowl until smooth. Stir it in this flour flurry into the beef mixture. It will thicken the sauce into a nice, glossy gravy.

Transfer the filling to a casserole dish and flatten with a spatula. Spread the mashed potatoes over the top and sprinkle evenly with cheese.

Bake in the 200 C / 400 F for 12-15 minutes until the cheese melts and turns golden brown.