1. Wash and trim fresh beans, if using. Cook, covered, in very large saucepan with a small amount of boiling water for 20 to 25 minutes or until crisp-tender. (Cook frozen beans according to package directions.) Drain beans; rinse with cold water and set aside.
2. Cook onion and garlic in olive oil over medium heat for 3 minutes or until tender. Stir in mustard, seasoning or pepper, and salt. Cook about 30 seconds more. Toss beans with onion mixture; heat through. Sprinkle with bacon.