Preheat a 4 quart soup pot over medium heat. Saute asparagus tips in oil with a pinch of salt for about 3 minutes. Remove about 10 tips for garnish and set aside.Turn the heat up a bit, add the asparagus stems, onion, garlic, tarragon, salt and pepper and saute for about 5 minutes, until onion is soft and garlic is golden.
Add chives, broth, beans and lemon juice and bring to a boil for 3 minutes.
Transfer to a blender and puree until completely smooth. The soup will be very hot so turn off the blender and remove the lid every 10 seconds or so to let steam escape. Serve into bowls and garnish with asparagus tips, extra chives and a swoosh of olive oil, if desired.