Bring a small saucepan of salted water to a boil. Add the haricots verts and cook briefly, about 1 minute. Transfer with a slotted spoon to an ice bath to refresh, then drain and pat dry. 

In a large skillet, melt the butter over medium-high heat. Add the drained and dried beans and season with salt and pepper. Cook, stirring, for 3 minutes, or until beans are crisp-tender. Transfer to a serving bowl or platter and garnish with hazelnuts and Parmesan cheese.