For extra crispy Brussels sprouts, make sure the pan is not crowded and always roast at high heat with the sprouts arranged cut side down. If your sprouts are very small, start checking them a few minutes early to prevent overbrowning. To add more keto fats and smoky flavor, toss in cooked chopped bacon with the Parmesan. Leftovers keep in an airtight container in the refrigerator for up to four days and reheat best in an air fryer or hot oven to restore their crisp edges. A squeeze of lemon or a pinch of red pepper flakes just before serving adds a bright or spicy twist without adding carbs.