Place a large skillet over high heat for 2 minutes. Season the flank steak all over with salt and pepper, then sear for 5 minutes. Flip and sear a further 5 minutes, or until the steak reaches an internal temperature of at least 135º F. Tent with foil and set aside.
In a large bowl, prepare the dressing: whisk olive oil, Dynasty Fish Sauce, lime juice, brown sugar, and Dynasty Sesame Oil until combined.
Add romaine, tomatoes, cucumbers, red onion, and mint leaves to the bowl and toss until coated. Place the salad onto a serving platter and top with slices of steak. Serve and enjoy!
