This soup has a rich, intense flavor that comes from roasting the fennel bulbs. It can be made even richer with the addition of Stilton cheese which melts luxuriously into the soup.
- ½ cup toasted walnuts, roughly chopped
- 8 fennel bulbs, stalks and fronds trimmed off
- 3 onions, peeled and quartered
- 4 sprigs rosemary
- ½ cup extra-virgin olive oil
- coarse salt and freshly ground pepper, to taste
- 10 cup vegetable broth
- ½ cup stilton (or other blue cheese) crumbled
- 1 teaspoon apple cider vinegar (optional)
- ¼ cup dried cranberries
- walnut oil, for drizzling
Preheat the oven to 350 degrees F. Place the walnuts onto a baking sheet and toast them until fragrant and light brown, about 6 minutes. Set aside
Raise the heat of the oven to 375 degrees F. Cut the fennel bulbs into quarters length wise. Choose 8 of the nicest slices and set them aside. On a parchment lined baking sheet lay the 8 nicest fennel slices in a single layer. Brush them with a bit of olive oil and a sprinkling of salt and pepper. Roughly chop the remaining pieces of fennel into 1 to 2‑inch chunks. Add these to a large bowl along with the onions, rosemary, remaining olive oil and a generous amount of salt and pepper. Toss the mixture to evenly coat the vegetables. Transfer to one or two additional parchment lined baking sheets, spreading the vegetables out into a single layer. Roast the all vegetables, until tender and well caramelized, about 1 hour; stirring once and rotating the pans halfway through cooking. The slices will probably be finished cooking a bit faster than the rest of the vegetables. Remove them and set them aside to garnish the soup at the end.
Discard the rosemary from the rest of the vegetables and transfer them to a large stock pot or Dutch oven. Add the stock. Bring the pot to a boil, then lower the heat to a simmer and cook the soup about 45 minutes. Turn the heat off and let the mixture cool completely before continuing.
Using an immersion blender, puree the soup until smooth. You want a velvety texture. Adjust consistency with a little more stock if necessary.
When you are ready to serve the soup gently reheat it until warmed through. Adjust seasoning with a little salt and pepper and (optionally) some apple cider vinegar.
Garnish the soup with the reserved roasted fennel slices and a drizzle of walnut oil. The walnuts, Stilton and dried cranberries may be served on the side as optional garnishes.