Preheat the oven to 200℃. Peel and cut the potatoes into equal pieces. Boil them for about 20 minutes, and drain. Meanwhile, heat the milk together with the butter until melted.
Mash the potatoes. Stir the warm milk and butter through the potatoes using a whisk and keep stirring until airy. Keep the puree warm with the lid on the pan.
While the potatoes are cooking, cut the garlic, celery, onion, carrot and mushrooms into pieces. Finely chop the thyme and rosemary.
Fry the chopped vegetables with the herbs in some oil in a frying pan for about 5 minutes. Add the tomato puree and fry for a while.
Add the 'minced meat' and fry until smooth. Then sprinkle with flour and let it fry for a while. Deglaze with red wine, let it boil and add the stock with the peas. Bring to a boil and let it simmer for about 5 minutes until you have a slightly thick liquid minced 'meat' mixture. Add more stock if necessary
Spoon the mixture into a large baking dish and spread the mashed potato on top of it. Sprinkle with grated cheese and breadcrumbs. Bake the pie in the middle of the oven for about 15 minutes until brown.