Place the wheatberries in a large saucepan and add the water. Bring to a boil over high heat, reduce the heat, cover the pan and simmer for about 50-60 minutes or until all the wheat is tender. Drain any remaining liquid and place the wheatberries in a bowl to cool. Add the black beans, avocado, bell pepper, tomatoes, red onion, cheese or meat if used, jalapeno pepper and oregano and toss to distribute ingredients evenly. In a small bowl whisk the olive oil, wine vinegar, mustard and cumin. Pour over the salad and toss the ingredients. Add salt and pepper to taste. Let the salad stand at least 30 minutes before serving.