Assemble the green bean bundles. Preheat the oven to 425 degrees. Lay a slice of prosciutto on your work surface. Place 8-10 green beans in the center of the prosciutto slice. Brush the green beans with olive oil. Sprinkle 1-2 tbsp of grated parmesan cheese over the green beans, then top with a pinch of rosemary.
Wrap the green beans. Grab the edge of the prosciutto and tuck it over the green beans. , then roll it tightly. Place the green bean bundles on a parchment paper lined baking sheet seam side down,
Bake the green bean bundles. Place the baking sheet on the middle rack in the oven and bake for 10-12 minutes.
Serve. Top the green bean bundles with more parmesan cheese, serve, and enjoy!