Preheat the oven to 375 degrees. Place the bacon pieces in a sauté pan over medium heat. Cook, stirring often, until most of the fat has been rendered out and the bacon is just barely starting to get crispy in a few places (it will finish cooking in the oven). Place the halved Brussels sprouts onto a sheet pan and pour over the bacon and all of the fat from the pan. Drizzle the olive oil over the top and sprinkle generously with salt and pepper. Toss the mixture together to thoroughly coat all of the sprouts with seasoning and transfer to the hot oven. Bake the hash for 22-24 minutes, stirring once during cooking. At this point, the bacon should be nicely crisp and the sprouts should be softened. Add the diced pears and the thyme leaves and toss together gently. Return the hash to the oven for 4 to 5 minutes just to warm the pears through. Serve immediately.