Cook the chopped bacon in a large skillet over medium heat until crisp. Remove the bacon and set it aside, leaving the drippings in the pan.
Season the beef cubes with salt and pepper. Brown them in the bacon drippings in batches until they have a deep color on all sides. Transfer the beef to the slow cooker.
Add the diced onion, minced garlic, and tomato paste to the skillet. Cook for two minutes, then stir in the flour and cook for one more minute. Pour this mixture into the slow cooker.
Add the cooked bacon, red wine, beef broth, sliced carrots, quartered mushrooms, thyme sprigs, and bay leaves to the slow cooker. Stir to combine everything.
Cover and cook on low for 8 hours or until the beef is fork-tender. Remove the thyme sprigs and bay leaves before serving.
Cook the egg noodles according to package directions. Drain them and toss with the butter while they are still hot.
Spoon the beef bourguignon over the buttered noodles and serve right away.