Creamy Leek and Parsnip Soup with Toasted Hazelnuts

Preheat oven to 350°F (175°C). Spread chopped hazelnuts on a baking sheet and toast for 8-10 minutes, or until fragrant and lightly golden. Watch carefully to prevent burning.

While the hazelnuts are toasting, heat olive oil in a large pot or Dutch oven over medium heat. Add the chopped onion and cook until softened, about 5 minutes.

Add the sliced leeks and minced garlic to the pot. Cook, stirring occasionally, until the leeks are softened and translucent, about 5-7 minutes.

Add the chopped parsnips and thyme sprig to the pot. Cook for another 2-3 minutes, stirring occasionally.

Pour in the vegetable broth. Bring to a boil, then reduce heat and simmer for 20-25 minutes, or until the parsnips are very tender.

Remove the thyme sprig. Carefully transfer the soup to a blender or use an immersion blender to puree until smooth.

Return the soup to the pot. Stir in the heavy cream (if using) and season with salt and pepper to taste.

Ladle the soup into bowls and garnish with toasted hazelnuts.