Spread the skirt steak across a large cutting board, and cut into sections that are approximately 4 inches long, cutting with the grain of the meat. Next, cut against the grain to slice each section into 1⁄4 inch strips.
Over medium-high heat, let the skillet get hot and melt the coconut oil. Place the steak in the skillet and allow it to brown on both sides, approximately 1-2 minutes per side. Remove the steak from the skillet and set aside.
Place the red onion, carrots, string beans, and bell peppers (or whatever vegetables you decide to use) in the pan. Cook for about 5 minutes or until fork-tender.
While the vegetables cook, combine the coconut aminos, rice vinegar, garlic, and ginger in a small bowl and mix well.
Add the meat back to the pan, followed by the sauce, and heat through for about 2 minutes.