Best-Ever Pepper Steak Recipe

Ingredients

• 1/4 c. low-sodium soy sauce
• 2 tbsp. rice wine vinegar
• 4 tsp. packed brown sugar
• 1 tbsp. cornstarch
• 2 tbsp. vegetable oil, divided
• Kosher salt
• Freshly ground black pepper
• 1 lb. flank steak, thinly sliced against the grain
• 1 red bell pepper, thinly sliced
• 1 green bell pepper, thinly sliced
• 3 cloves garlic, minced
• 1 tbsp. freshly minced ginger
• Cooked white rice, for serving