Rinse the beans in cold water. Trim ends if necessary.
Over medium-high heat, bring a large pot of salted water to a boil. Add the beans and blanch until slightly softened, 3-5 minutes. Drain the beans well.
In a skillet over medium-high heat, melt the butter and olive oil together. Add the blanched and drained beans. Cook, stirring, until the beans are crispy, soft, and hot, about 3 minutes. Remove the pan from the heat.
Sprinkle the beans with the parsley, nuts, and salt and pepper to taste. Toss well. Serve immediately.