Preheat the oven to 425°F. Place the flatbread on a sheet pan.
Using a knife or kitchen shears, trim the flatbread into a heart shape (cut a small V-notch at the top and round the sides).
Whisk soy sauce, gochujang, honey, sesame oil, ginger, and garlic. Reserve 2 tbsp for brushing, then toss the beef with the remaining marinade and a pinch of salt and black pepper; let sit 10 minutes.
Brush the flatbread with the reserved sauce. Bake 4–5 minutes, until warmed through and lightly crisp at the edges.
Heat vegetable oil in a large skillet over medium-high. Lift beef from the marinade (let excess drip off) and cook in an even layer 2–3 minutes, stirring once or twice, until browned and just cooked through; remove from heat.
Scatter the cooked beef over the toasted flatbread, then return to the oven 2–3 minutes to warm everything through.
Prepare the Fresh Express® Orange Sesame Chopped Kit by adding the greens to a large bowl. Drizzle the dressing over the greens and toss to lightly coat. Sprinkle with included toppings.
Top the warm flatbread with the prepared salad, then cut into strips for serving and enjoy!