Preheat your oven to the temperature recommended on the mushroom pie packaging. Place the pie on a baking tray and cook according to package instructions, usually about 25-35 minutes.

For the mash, peel and chop 800 grams of potatoes into chunks. Boil in salted water until tender, about 20 minutes. Drain, then mash with 50ml of milk and 25 grams of butter until smooth. Season with salt and pepper to taste.

Peel and slice 4 carrots. Boil or steam along with 200 grams of peas until tender, about 10-15 minutes.

For the Yorkshire puddings, mix 140 grams of plain flour, 4 eggs, and 200ml of milk into a smooth batter. Preheat Yorkshire pudding tins with a little oil in each cup in the oven until very hot. Pour the batter into the tins and bake at 220°C (428°F) for 20-25 minutes until puffed and golden. Do not open the oven door while baking to ensure they rise properly.

Serve the mushroom pie with a side of mash, carrots, and peas. Add Yorkshire puddings to each plate for a complete meal.