Cook beans in boiling water in large uncovered saucepan on medium-high heat 3 minutes or until tender-crisp. Drain immediately and rinse with cold water. Set aside.
Melt butter in large skillet on medium-high heat. Add onion; cook and stir 3 to 4 minutes or until tender. Add green beans; cook and stir 1 to 2 minutes. Add Seasoning; toss to coat well.