Wash hands with soap and water.

Wash red or green pepper and cilantro (if using).

Wash and juice the lime into a small bowl (if using).

Drain and rinse the black beans and corn (if using canned corn).

Collect, mince, and measure all ingredients.

Bring chicken broth to a boil in a small pot, and stir in couscous.

Cover the pot and remove it from the heat. Let stand for 5 minutes.

In a large bowl, whisk together oil, vinegar, cumin, and lime juice (if using).

Add beans, onion, red or green pepper, and corn to the vinegar and oil mixture, and toss.

Fluff the couscous well with a fork, breaking up any chunks. Add to beans and vegetables, and mix well.

Taste. Add salt and black pepper if desired.

Add cilantro (if using) and serve.