How to Make It
Cook beans in salted water to cover 3 to 5 minutes or until slightly crunchy and still bright green. Plunge into ice water to stop the cooking process. Drain and set aside.
Sauté mushrooms in 2 tablespoons butter over medium-high heat 3 minutes.
Combine mushrooms, beans, and remaining butter, and toss to coat. Season to taste with salt and pepper.