Fresh green and yellow beans dressed with a mustard vinaigrette make a tasty side-dish salad for grilled meats. Leave the beans whole for visual impact.
1. Whisk vinegar and mustard in small bowl. Whisk in oil, salt and pepper.
2. Steam beans until crisp-tender, 10 minutes. Run beans in colander under cold water to stop cooking; drain.
3. Combine beans and onion in serving bowl. Add dressing. Let stand at room temperature 30 minutes. For best flavor, refrigerate overnight; serve at room temperature.