Cut the stems off the Brussels sprouts. In a food processor fitted with the slicing attachment, shred the Brussels sprouts. You might have to do it in batches depending on how large your food processor is. You can also thinly slice with a knife if you don't have one.
Heat large skillet over medium-high heat. Add bacon and cook until crisp, about 5-8 minutes. Remove bacon and add to paper towel-lined plate.
Reserve about ¼ cup bacon fat in skillet. Add Brussels sprouts and sauté for about 10 minutes or until your desired doneness. Remove from heat and add bacon. Season with salt and pepper to your liking. Serve immediately.
Notes
Use a food processor with a slicing attachment to shave the Brussels sprouts quickly and safely.
If you don't want to cook the Brussels sprouts in bacon fat, use unsalted butter instead.
Add some sautéed shallots if you want additional flavor.