Steam broccoli florets and stems until tender
and bright green, about 3 minutes. Let cool slightly.
Reserve 1/2 cup florets for garnish.
Heat oil in a medium pot over medium heat. Saute onion and garlic until translucent, about 6 minutes.
Add beans and stock and bring mixture to a simmer.
Remove from heat and add broccoli; puree in batches in a blender until smooth. Season to taste with salt and pepper. Garnish each bowl with broccoli florets, toasted pine nuts, and shaved Parmesan.