In large saucepan, heat butter over medium heat until hot. Cook and stir onion and garlic 8 to 10 minutes or until onion is soft and lightly browned. Add squash, potato, dried plums, water, rosemary and bouillon; bring to a boil, stirring occasionally. Reduce heat; simmer, uncovered, 20 to 25 minutes or until vegetables are very soft.
Remove from heat; cool slightly. Working in small batches, process vegetable mixture in blender container until smooth; return to pan. Whisk in sour cream; season with salt and pepper. Heat through before serving.
– To make acorn squash easier to peel, heat whole squash in microwave oven 3 to 4 minutes or until slightly softened; peel off skin.
– If desired, garnish individual bowls with sour cream drizzle. In small bowl, whisk together ¼ cup reduced-fat sour cream and 1 tablespoon water until smooth. Drizzle over soup just before serving
Recipe courtesy of California Dried Plum Board.