Prepare sauce by adding Gochujang sauce, sesame oil (or water), coconut aminos, maple syrup, sea salt, and chili garlic sauce to a small mixing bowl and mix to combine. Taste and adjust flavor as needed, adding more chili garlic sauce for heat, maple syrup for sweetness, or coconut aminos for depth of flavor / saltiness. Set aside.
Make sure your Brussels sprouts are rinsed, dried, and halved and any large stem portions are removed.
Heat a large cast-iron or metal skillet over medium-high heat. Depending on the size of your skillet (ours was a 12-inch cast iron), you may need to cook the Brussels in two batches so they get evenly cooked and don’t crowd the pan.
Once hot, add sesame or avocado oil (or water) to the pan and Brussels sprouts (know that oil is better for frying and caramelizing the sprouts). Season with the coconut aminos and toss to combine. Then evenly spread the Brussels sprouts in the pan so each one is touching the surface of the pan (remove any that are crowded).
Cover and cook for 2 minutes. Then remove lid and stir-fry uncovered for 2 minutes more, stirring occasionally to brown all sides. Turn down heat if needed if any are appearing too brown.
Once the Brussels sprouts appear to be caramelized, add the sliced shallot or green onion (optional) and the prepared sauce and stir-fry for 1-2 minutes more to coat and caramelize the sprouts even more. Then turn off heat and transfer to a serving platter. Garnish with crushed peanuts if desired (optional). Enjoy hot.
*Nutrition information is a rough estimate calculated with sesame oil and without optional ingredients. *If you'd rather roast your Brussels Sprouts, simply toss in the marinade then roast on a baking sheet at 400 degrees F (204C) for 15-23 minutes, tossing near the halfway point to ensure even baking. You'll know they're done when the exterior has a deep brown color but the interior still has a little bite.