In a medium pot of boiling salted water, cook the orzo, stirring occasionally, until al dente, about 8 minutes. Drain; return to the pot. Stir in 2 tablespoons olive oil, cover and set aside.
In a large nonstick skillet, heat 2 tablespoons olive oil over high heat. Add the eggplant and cook for 1 minute. Add 2 tablespoons olive oil, the onion and broccoli rabe stems and cook for 2 minutes. Stir in the broccoli rabe leaves, cover and cook until wilted, about 4 minutes. Transfer the vegetables to a large bowl and season with salt.
Wipe out the skillet, add 1 tablespoon olive oil and heat over medium-high heat. Working in 2 batches, add the steak strips and fry for 1 minute; repeat with the remaining 1 tablespoon olive oil and steak strips. Return all the steak to the skillet and move to one side of the pan. On the other side of the pan, whisk together the beef broth and tomato paste and cook until the liquid is reduced by half, about 2 minutes. Remove from the heat and quickly whisk in the hummus to form a sauce. Stir the steak into the sauce, then stir in the reserved vegetables.
Place a mound of orzo on each plate and top with the steak stir-fry.