Blanch the green beans in lightly salted boiling water until tender and bright green, 3- 4 minutes. Plunge into cold water, drain when cool, set aside.
Melt the butter in a large heavy skillet over medium heat. Add the balance of the ingredients and saute gently for 2-3 minutes. Season with salt and pepper. Place green beans in a serving dish and pour sauce over green beans.
Or, you may add the green beans to the sauce, season with salt & pepper and toss to coat.