Rub the steaks with oil and salt and pepper, red pepper flakes and garlic powder and place on the grill. Cook for 2-3 minutes on each side, until the steaks reach the desired level of doneness and then set aside.
In a large skillet over medium heat, heat the avocado oil. To the skillet, add the remaining ingredients and cook for 10 to 15 minutes, until Brussels sprouts are tender.