Trim broccoli by removing the florets and cutting them into bite-size pieces. Peel stem and dice.
Blanch in boiling, salted water for 30 seconds or until tender and place in ice water.
Brown proscuitto in olive oil and remove from pan. Sauté onions, garlic, salt and broccoli stems in the same pan over low heat until tender (do not brown). Add chicken stock and simmer for 20 minutes.
Purée veggies in a blender. Pour into a bowl and garnish with broccoli florets, proscuitto and top with sour cream, pumpernickel crisps, cheddar or Parmesan tuile.