Heat olive oil over medium heat heat in a large skillet. Add in onions and saute until fragrant, 1-2 minutes. Add in chicken, garlic and ginger, and cook, while breaking up with a wooden spoon, until browned.
Remove chicken from skillet, and add in the cabbage. Cook until wilted and mostly tender, about 4-5 minutes.
Return the cooked chicken to the pan. Stir in sesame oil, soy sauce, vinegar, and sriracha. Season with salt and pepper and more sriracha as desired.