Preheat oven to 425° F. Line a baking sheet (it should have a lip so sprouts doesn't escape) with a piece of parchment paper or a silicone mat.
Mix together the brussels sprouts, 3 tablespoons oil, and salt on the baking sheet. Spread out into a single layer and pop into oven for 30 to 45 minutes (give or take) or until the brussels sprouts are partially browned and crispy. Stir halfway through for more even roasting.
For Crispy Onions
Meanwhile, in a small saucepan, heat the 1 tablespoon oil. Add the onion and saute, stirring frequently, over medium heat until the onion is browned and crispy caramelized.
Remove onions from the saucepan and set aside on a paper towel.
For Soy Glaze
Whisk together the liquid aminos, allulose, molasses, ginger, garlic powder, and black pepper over medium-high heat. Allow to heat, stirring frequently, until sweetener has dissolved and the mixture has somewhat thickened. If you'd like it to be thicker, sprinkle on the xanthan gum and stir in after removing from the heat.
Finishing Up
Put the roasted brussels sprouts in a bowl or serving dish. Drizzle with glaze (mix it in if you'd like it to be more even) and sprinkle the crispy onions on top (also mix in if you like).
Notes
Note that on Trim Healthy Mama, this recipe has negligible carbs because we do not count the ones in non-starchy veggies like brussels sprouts. The nutrition label, however, does.