Wash the green beans and trim the ends. Slice the mushrooms and mince the garlic.

Bring a pot of salted water to a boil. Add the green beans and cook for 2-4 minutes until they are vibrant green but still crisp. Drain and plunge them into an ice bath to stop the cooking.

In a large skillet, heat 2 tablespoons of olive oil over medium heat. Add the sliced mushrooms and cook until golden brown, about 5-7 minutes. Season with salt, pepper, and red pepper flakes if desired.

In the same skillet, pour in the remaining olive oil and add the minced garlic. Sauté until fragrant, about 1 minute. Then add the blanched green beans and stir to heat them through.

Add the sautéed mushrooms back to the skillet with a splash of soy sauce. Toss everything to coat, then stir in the butter until melted. Garnish with freshly chopped parsley or chives before serving.