Heat 1 tablespoon of the oil in a medium skillet over medium-high heat.
Season the steak with ½ teaspoon each salt and pepper and cook, 3 to 5 minutes per side for medium-rare. Transfer to a cutting board; let rest.
Wipe out the skillet and heat the remaining oil over medium heat. Add the mushrooms and cook for 3 minutes. Add the wine and cook until it has evaporated.
Add the orzo and chicken broth and simmer until the broth is absorbed, about 10 minutes. Stir in the Parmesan, rosemary, and ¼ teaspoon pepper.
Meanwhile, steam the broccoli rabe in a separate pot until tender, about 5 minutes. Drizzle with the lemon juice.
Divide the broccoli rabe among plates. Serve with the steak and “risotto.”