Orzo pasta (prepared according to package directions) will work in place of couscous.
Prepare couscous according to package directions.
Brush chicken with 1 Tbsp. oil; sprinkle with 3/4 tsp. salt and 1/4 tsp. pepper.
Cook chicken, covered, in a large nonstick skillet or grill pan, over medium-high heat 8 to 10 minutes on each side or until done.
Meanwhile, combine tomatoes, next 4 ingredients, and remaining 1 Tbsp. oil, 1/2 tsp. salt, and 1/4 tsp. pepper. Stir tomato mixture into prepared couscous.
Divide couscous mixture, hummus, and pita bread quarters among 4 serving plates; top each with 1 chicken breast.