Easy Stir Fried Beef with Vegetables

Bahan-bahan (4 porsi)

• 16 ounces flank steak
• 6 tablespoons soy sauce
• 4 teaspoons cornstarch
• 2 tablespoons water
• 1 teaspoon granulated white sugar
• 3 tablespoons vegetable oil, (divided)
• 1 medium onion, (thinly sliced)
• 2 medium bell peppers, (thinly sliced)
• 1 cup sliced mushrooms
• 1 cup sliced zucchini
• 1 medium carrot (thinly sliced)
• 2 teaspooons grated fresh ginger
• cooked rice, (for serving (optional))