Rich Venison and Porcini Pie with Cheesy Puff Pastry

Heat 1 tablespoon of vegetable oil in a large, deep, flameproof casserole dish over high heat. Once the oil is shimmering, add the chopped bacon and cook for 5-6 minutes until crisp and golden. Use a slotted spoon to remove the bacon to a bowl and set aside.

In a shallow bowl, whisk together the flour, mustard powder, and a generous amount of seasoning. Toss the venison pieces in the flour mixture, shaking off any excess. Brown the meat in the residual bacon fat in batches, adding the remaining oil 1 tablespoon at a time if the pan becomes dry. Transfer the browned venison to a plate. If the pan bits look overly dark, deglaze with a splash of water, scrape the bottom, and discard the liquid before proceeding.

Melt the butter in the same casserole dish. Once foaming, add the celery, carrot, and red onion, sautéing for 10-12 minutes until softened. Stir in the garlic for 3-4 minutes, then add the tomato purée and cook for another 2-3 minutes until it darkens. Pour in the rehydrated porcini mushrooms along with their filtered soaking liquid, the red wine, and beef stock. Add the bay leaves and thyme, then return the venison and bacon to the pan. Cover and simmer over low-medium heat for 2 to 2.5 hours, removing the lid for the final 20 minutes to ensure the sauce is thick and glossy.