Make the flatbread: Preheat the oven to 450 degrees F. Whisk the hummus, 1/3 cup hot water, the cumin, rosemary and 1 tablespoon olive oil in a bowl. Whisk in the flour and a pinch each of salt and pepper. Set the batter aside, 30 minutes.
Heat a 12-inch cast-iron skillet over high heat. Add the remaining 1 tablespoon olive oil and swirl to coat the pan. Pour in the batter and spread to the edges with a spatula. Transfer to the oven and bake until firm, and crisp and golden around the edges, 25 to 30 minutes. Let sit 5 minutes in the pan.
Make the salad: Toss the parsley, bell pepper, scallions, olives, olive oil, lemon juice and salt and pepper to taste in a bowl.
Use a spatula to scrape shards of the flatbread onto plates. Serve with the parsley-olive salad.