Use of foil makes cleanup a snap.
Preheat oven to 450°F. In a large pot fitted with a steaming basket, bring 1 inch of water to boil. Add green beans to the basket and steam until crisp-tender, 10 minutes. Remove from basket, drain, and combine with chickpeas and kidney beans. In a small mixing bowl, combine olive oil, vinegar, chives, parsley, pepper, and 1 teaspoon of basil. Toss with beans, cover, and refrigerate for at least 30 minutes. Place chicken in a large piece of foil. Top the chicken with tomato sauce and sprinkle with the remaining 1/2 teaspoon basil, garlic, and cheese. Fold foil loosely over chicken, leaving ample space for air. Carefully turn up and seal the ends and the middle so that juices won't leak out. Bake for 20 minutes. Remove from the oven and carefully open foil to prevent steam burns. Serve with bean salad.