Mediterranean Avocado and Black Bean Salad

1 pint cherry tomatoes , halved

red onion , large, minced (about 2/3 cup)

1 cup cilantro , fresh, finely chopped

1 red bell pepper , seeded and finely chopped

1 green bell pepper , seeded and finely chopped

2 (15 ounce) cans black beans , rinsed and drained

cup olive oil

2 limes , juice of (I prefer to use 3 small key limes but either will work)

salt & freshly ground black pepper , to taste