Place the steaks in a large mixing bowl and set aside. In a small bowl stir the salt, sugar, and pepper together. Sprinkle the salt mixture over the beef and toss to coat. Set aside.
In a small bowl whisk the soy sauce, fish sauce, honey, and lime juice together. Pour the mixture over the seasoned beef and toss to coat. Transfer the beef to the fridge and let marinate for at least 1 hour or up to 3.
When you're ready to cook, take the scallions and remove the white ends from the green. Slice the white ends thin and slice the green sections into larger chunks and set aside.
Add the oil to a wok and place over medium-high heat. Once the oil is shimmering, add the beef and white scallions to the wok. Stir-fry the beef until browned and caramelized but still tender. About 3 minutes. Stir in the green scallions and saute until just wilted, about 2 minutes more.
Place the cilantro and lettuce in a large bowl. Pour 1/4 cup of the pickling liquid from the red onions over the greens and toss to coat. Transfer the greens to a large platter and decorate with cucumber slices, tomato wedges and radishes. Spoon the hot beef over top of the lettuce and sprinkle with pickled red onions. Decorate the platter with additional lime wedges and serve immediately with rice, if desired.