One day a few weeks ago, I returned home to find a folded piece of paper stuck inside my screen door. It took but a moment to figure out who had left it, as Debbie and I were talking earlier about a blueberry soup recipe she wanted me to try. The recipe, from Yankee magazine, came with notes suggesting some changes, and when Bob handed me a couple of cups of gorgeous blueberries from his garden, I knew the time had come. I went far afield of the original version in creating this no-cook blueberry apple soup, substituting a small amount of agave nectar for the sugar, and eliminating the sour cream, but I kept the cinnamon-coriander spice combination because it warms up the tart blueberries. If you prefer an absolutely seedless soup, pass the mixture through a food mill. A scoop of lime sherbet would send this straight to dessert heaven.