Tomatillos stand in for the ripe red tomatoes that are the usual base for this cold summer soup from Spain. Toasted walnuts take the place of the bread that thickens the soup. Green tomatoes make an interesting substitute for the tomatillos. For a sweet flavor boost, roast 6 to 8 peeled garlic cloves along with the tomatillos and puree them with the other ingredients.
Recipe courtesy of Williams-Sonoma. Adapted from Williams-Sonoma Lifestyles Series, “Vegetarian for All Seasons”, by Pamela Sheldon Johns (Time-Life Books, 1998).