Place lamb into a mixing bowl and toss together with smoked paprika, cumin, coriander, ground ginger, salt, and pepper. Refrigerate for 1 hour.
While lamb marinates, make hummus: Place garbanzo beans, plus reserved liquid, tahini, oil, garlic, lemon juice, and salt into the well of a blender and puree until silky smooth (adding water 1 to 2 tablespoons at a time, as needed). Adjust seasonings, cover and set aside.
Remove lamb from refrigerator and allow mixture to sit at room temperature for 15 minutes.
Place a large skillet over medium-high heat. Once skillet is hot, add oil followed by lamb and sauté for 3 to 4 minutes. Lower heat to medium and continue to cook lamb for an additional 4 to 5 minutes or until cooked through, but still slightly pink in the center. Adjust seasonings. Remove from heat and set aside.
To assemble: Pour hummus into a large bowl and make a well in the center (can easily do this with the back of a ladle). Fill hummus well with spiced lamb and top with chopped parsley and mint. Serve with grilled pita bread.