In a bowl, stir together the gochujang, gochugaru, soy sauce, mirin, honey, garlic, ginger, and sesame oil into a smooth paste. Add the chicken and toss until every piece is coated. Let it sit for 15 minutes while you cut the vegetables, or up to overnight in the fridge.

Heat the neutral oil in a large skillet or cast iron pan over medium-high until it shimmers. Add the sweet potato slices in a single layer and cook 3 to 4 minutes, turning once, until they start to soften at the edges. They take the longest, so they go in first.

Push the sweet potato to one side and add the marinated chicken in a single layer. Let it sit undisturbed for 2 minutes to catch some color, then stir. Cook 5 to 6 minutes until the chicken is nearly cooked through and the sauce is sticky.

Add the cabbage and onion. Stir-fry 4 to 5 minutes until the cabbage wilts but still has a little bite. The vegetables will release moisture and loosen the sauce, which is what you want.

Add the scallions and toss for one more minute. Check that the chicken reads 165F at the thickest piece. Taste and add a splash more soy sauce or a pinch of gochugaru if you want it hotter.

Kill the heat, scatter over the sesame seeds, and serve straight from the pan. It is great over rice or on its own if you are watching carbs.