Season the sirloin with salt and pepper. Sear the steak in a heavy-bottomed pan for 4 to 5 minutes until medium rare.
In a large bowl whisk together lemon juice, salt, ground cumin, and olive oil. Add scallions, cucumbers, tomatoes, chickpeas, parsley, and mint. Toss to combine. Add spinach and pita. Toss to combine, taste and adjust seasonings.
Thinly slice the sirloin (portion control the meat according to your needs). Mound the salad onto a large plate. Top with overlapping pieces of the sirloin steak. Serve immediately.
Preheat the oven to 350 degrees F.
Cut each pita into 8 pieces. Lightly spray the pita with olive oil. Sprinkle with cumin and season with salt and pepper, to taste. Place on a baking sheet and bake until crisp, shaking the pan halfway through cooking, about 10 to 15 minutes