Cream of Asparagus Soup

Amazingly, I have never made this soup before.  Two things conspired to change that.  The first was that my spouse let me know that he is not all that fond of asparagus.  What?  Really?  Well, what to do with the bunch that I have had in my fridge for at least two weeks?  It was not even deteriorating so the tips could be saved for soup, even.  The second is that the six cups of stock my spouse had saved for me from his last batch was in need of a soup to go in, and my plan to make lentil soup was an epic fail after I dropped the jar of dried French lentils on my granite counter and the shattered glass comingled with the lentils in such a way that I decided the safest thing to do was to put them all into the trash.
So, Cream of Asparagus Soup it is.  And what a simple recipe!

• 2 pounds green asparagus
• 1 large onion, chopped
• 1-2 small potatoes diced
• 5 to 6 cups  broth
• 1/2 cup half and half
• 1/4 teaspoon fresh lemon juice, or to taste

1. Cut off bottom of the stalks from a bunch of asparagus
2. 1 1/2 inches from top and halve tips lengthwise if thick. Reserve for garnish.
3. Cut stalks and all remaining asparagus into 1/2-inch pieces. Dice potatoes and chop onion.
4. Cook onion,  asparagus pieces, salt and pepper to taste, and 5 cups broth and simmer, covered, until asparagus is very tender, 15 to 20 minutes.
5. Purée soup in batches in a blender until smooth, transferring to a bowl (use caution when blending hot liquids), and return to pan. Stir in half and half, then add more broth to thin soup to desired consistency. Season with salt and pepper.
6. Add lemon juice and garnish with asparagus tips.