Place the strip steaks in a resealable plastic bag. Combine the crushed garlic, brown sugar, oyster sauce, fish sauce, sesame oil, and low-sodium soy sauce in a small bowl. Stir well, then pour into the plastic bag. Press out the air and seal the bag tightly. Let the meat sit on the counter for 30 minutes or until it comes to room temperature.
Preheat your oven to 450 degrees Fahrenheit (230°C) and place a cast iron skillet inside. Open your windows and turn on the fan for ventilation. Once the oven is preheated, carefully transfer the hot pan to a stove-top burner and set the heat to medium.
Place the marinated steaks in the pan and let them sear for 2 minutes. Flip the steaks and turn off the stovetop heat. Return the pan to the oven and let cook for 4 to 6 minutes, until the steaks reach the desired doneness. Let the steaks rest for 5 to 10 minutes before serving.
Notes
To store Vietnamese Steak, place leftovers in an airtight container and refrigerate for up to 3 days. For longer storage, freeze the steak, tightly wrapped for up to 2 months.To reheat, thaw frozen steak overnight in the refrigerator. Warm it in a skillet over medium heat for a few minutes, or wrap it in foil and heat in a 300°F (150°C) oven until warmed through.