Preheat oven to 425. Line a rimmed baking sheet with parchment paper.
Add bacon pieces to the baking sheet and cook for 8 minutes.
Meanwhile, make the sauce. Combine coconut aminos, oil, vinegar, garlic, fish sauce, and red pepper flakes in a small bowl and whisk well. Add the chopped brussels sprouts to a bowl and pour the sauce over them. Toss to coat well.
Remove the bacon from the oven and add the sauce-coated brussels sprouts. Toss to combine so the bacon fat is mixed in with everything else.
Cook for an additional 15 minutes or until the brussels sprouts and bacon are crispy.