Preheat oven to 400 degrees.
Drizzle trimmed & halved brussel sprouts with olive oil. Add dijon mustard and apple cider vinegar and coat evenly.
Salt & pepper to taste and add to a baking sheet.
Roast for 15 minutes. Flip brussel sprouts and add bacon. Roast for an additional 10-15 minutes or until desired doneness.
If making this a Paleo-friendly (not low-carb or keto-friendly) add 2 tsp maple syrup with dijon mustard.