This is very refreshing and a little different from the usual gazpacho. I use an immersion blender to puree the tomatillos rather than a regular blender. Adapted from Fine Cooking, June/July 2007. (Time does not include refrigeration time.)
Heat broth over medium-high heat. Add tomatillos and garlic; bring to boil. Reduce heat and simmer until tomatillos are cooked through but still hold their shape, about 1 minute. Let cool slightly, about 5 minutes, then carefully puree mixture in blender along with olive oil.
Cool completely, then stir in remaining ingredients. Season to taste with salt and pepper. Refrigerate at least one hour before serving.