Preheat broiler. Line a large shallow baking pan with foil. Stir together oil, salt, cumin, pepper, and oregano in a large bowl, then toss with chicken and vegetables. Arrange in baking pan without crowding and broil 4 to 6 inches from heat, stirring once, until chicken is just cooked through and vegetables are lightly charred, about 8 minutes. Divide hummus among plates and top with chicken and vegetables.