<ul><li>1 lb flank steak, thinly sliced</li><li>2 tbsp soy sauce</li><li>1 tbsp oyster sauce</li><li>1 tbsp hoisin sauce</li><li>2 tbsp rice vinegar</li><li>1 tbsp sesame oil</li><li>1 tbsp vegetable oil (for stir-frying)</li><li>1 onion, sliced</li><li>1 bell pepper, sliced</li><li>1 zucchini, sliced</li><li>1 carrot, julienned</li><li>2 garlic cloves, minced</li><li>1-inch piece of ginger, minced</li><li>1-2 red chili peppers, chopped (adjust to heat preference)</li><li>2 tbsp cornstarch (optional, for thickening)</li><li>Fresh cilantro (for garnish)</li><li>Cooked rice (for serving)</li></ul>