Prep your veggies. Slice the cabbage thinly, cut the onion into slivers, and mince the garlic and ginger.
Keep them close by—this moves fast once you start cooking.
Brown the beef. Heat a large skillet or wok over medium-high. Add the ground beef and cook, breaking it up, until browned and slightly crispy at the edges. Season with a pinch of salt and pepper.
If there’s excess fat, spoon off a little, but leave some for flavor.
Sauté aromatics. Push the beef to the side. Add the onion to the empty space and cook 2–3 minutes until softened. Stir in the garlic and ginger and cook 30 seconds until fragrant.
If the pan looks dry, add a teaspoon of oil.
Add the cabbage. Pile it in and toss with the beef mixture. It will look like a lot, but it wilts quickly. Cook 5–7 minutes, stirring often, until the cabbage is tender with a slight crunch.
Make it saucy. Stir in soy sauce, rice vinegar, and sesame oil.
Add chili garlic sauce if you like heat. Taste and adjust seasoning—more soy for savory depth, vinegar for brightness, or sesame oil for nuttiness.
Finish and garnish. Turn off heat. Fold in the green onions and sprinkle with sesame seeds.
Serve hot.