Pat the steaks dry with a paper towel. Cut into 1-inch cubes. In a medium bowl, whisk 1 tbsp. oil, 1 tbsp. honey, the soy sauce, garlic and 1/8 tsp. salt. Toss with the steak; marinate at room temperature 20 minutes.
Meanwhile, zest and juice 1 1/2 limes. In a large bowl, whisk lime juice, 1 tbsp. oil and the remaining 1 tbsp. honey until smooth. Season and transfer 1 tbsp. to a small bowl; mix in half the onion and toss to coat. Let the onion marinate while you cook the steak.
Heat the remaining 1 tbsp. oil in a wok or large cast-iron skillet over high. Carefully add the steak in a single layer; cook until browned on all sides, about 5 minutes.
Add the romaine, tomatoes and the remaining onion to the large bowl with the vinaigrette; toss to coat. Divide the salad among bowls; top with the beef, lime zest and marinated onion. Serve with 1/2 lime, cut into 4 wedges, and baguette slices.