1. Preheat oven to 350 degrees. Place almond slivers on a rimmed baking sheet; toast until golden brown, shaking the pan halfway through, about 10 minutes. Transfer to a board and chop; set aside.

2. Heat 2 tablespoons butter in a large saucepan over medium-low heat. Add onion; cook, stirring occasionally, until soft, about 10 minutes. Add leek; cook, stirring occasionally, until soft, about 5 minutes more. Add pumpkin, turnip, carrots, parsnip, 2 teaspoons salt, and pepper; cook, stirring, until the vegetables are well mixed and coated with butter.

3. Add 3 1/2 cups stock and thyme; bring to a boil over medium heat. Return heat to medium-low; gently simmer until vegetables are very tender, about 30 minutes.

4. Fill a saucepan with cold water. Add 1/2 teaspoon salt and rice. Bring to a boil over high heat; reduce heat. Simmer until rice is tender, about 45 minutes, or according to package instructions. Drain; set aside.

5. Remove soup from heat; let cool slightly. Use an immersion blender or puree in a food processor or blender (fill blender only halfway -- hot liquids expand). Working in batches, add stock to thin if necessary. Reheat soup over medium-low heat.

6. Heat remaining tablespoon butter in a saute pan over medium heat. Add apple; cook until brown and soft, about 3 minutes. Add scallions, remaining salt, and cayenne; cook until scallions soften, about 1 minute. Add rice and reserved nuts; cook until heated through, 1 to 2 minutes more.

7. Ladle soup into pumpkin bowls, and garnish with wild-rice mixture. Serve.