Preheat the oven to 325 degrees.
In a large covered ovenproof casserole dish or sauté pan, sauté the bacon over medium heat for 2 to 3 minutes until lightly browned. Remove bacon with a slotted spoon, reserving the grease, and drain on paper towels. Set aside.
Add the oil to the bacon grease. Reheat it until it's shimmering and almost smoking.
Dry the venison meat with paper towels to ensure that it will brown properly. Season with salt and pepper. Brown the meat in the oil in batches. Remove the meat with a slotted spoon, reserving the oil, and set aside with the bacon.
Sauté the carrots and sliced onion for 3-5 minutes or until lightly browned.
Add the garlic and sauté for 30 seconds.
Add the black pepper and flour and continue to sauté, stirring frequently, to remove the raw flour flavor, about 2-3 minutes more.
Add the wine and the broth, scraping up any browned bits on the bottom of the pan.
Stir in the tomato paste, thyme, bay leaves and pearl onions.
Return the venison and bacon to pan and toss with the vegetables.
Cover the pot and place it in the bottom third of the oven. Braise for 2-1/2 to 3 hours or until the meat pierces easily with a fork.
Forty-five minutes before serving, sauté the mushrooms in butter for 3-5 minutes until tender. Add the mushrooms to the pot and continue cooking.
Serve stew over mashed potatoes or egg noodles.