This plant-based soup is naturally creamy and uses the best of the season's produce – the spiced sourdough croutons add a divine crunch

This luxuriously creamy (yet dairy-free) soup is one of chef Clodagh McKenna's favorite entertaining dishes for fall, as it showcases an often overlooked vegetable that is prolific on her farm at this time of year. In our exclusive How I Host video with Clodagh McKenna, she shares how she makes this rustic and flavorful starter from her new book, Clodagh's Happy Cooking, and you can find the full recipe below.

Ingredients (serves 4)

• For the soup
  • 1 ¾ pounds (800 g) cauliflower florets
  • 1 medium onion, chopped
  • 2 teaspoons ground turmeric
  • 1 teaspoon ground cumin
  • 2 tablespoons olive oil
  • 1 cup (5 oz / 150 g) roasted cashews
  • 3 cloves garlic, crushed
  • 1 tablespoon finely chopped fresh sage (these herb scissors from Amazon are perfect for the job)
  • 4 cups (1 quart / 1 liter) hot vegetable broth
  • Juice of 1 lemon
  • Sea salt and freshly ground black pepper, to taste
• For the aromatic sourdough croutons
  • 4 slices sourdough bread, cut into small cubes
  • 2 tablespoons olive oil
  • 2 teaspoons garam masala
  • Sea salt and freshly ground black pepper

Clodagh McKenna's method

• Preheat the oven to 400°F (200°C) convection or 425°F (220°C) conventional.
• On a large baking sheet (we love this Caraway non-stick ceramic baking sheet), spread out the cauliflower florets and chopped onion. Sprinkle over the turmeric, cumin, salt, and pepper, then drizzle with 2 tablespoons of olive oil. Toss to coat evenly.
• Roast for 25 minutes, until the cauliflower is tender and slightly charred at the edges.
• After 10 minutes of roasting, remove the tray from the oven, add the cashews, garlic, and sage, toss again, and return to the oven for the remaining 15 minutes.
• While the vegetables roast, make the croutons
  • Place the cubed sourdough bread on a separate baking sheet.
  • Drizzle with 2 tablespoons olive oil, sprinkle with garam masala, and season with salt and pepper.
  • Toss to coat evenly and roast in the hot oven for about 10 minutes, or until the croutons are crisp and golden brown.
• Once the vegetables are roasted, transfer them (and any pan juices) to a blender or food processor (we recommend the Ninja Professional Plus kitchen system in our guide to the best blender food processor combos). Pour in the hot vegetable broth and blend until completely smooth.
• Transfer the blended soup to a saucepan or Dutch oven (this Lodge Dutch oven is a reliable buy that will last years), stir in the lemon juice, and warm gently over low heat. Taste and adjust seasoning as needed.
• To serve: Ladle the hot soup into warmed bowls and top generously with the garam masala croutons, (try Martha Stewart's square ladle and you won't go back).

If you love warming soups at this time of year, try our herby fennel and cannellini bean soup with ricotta, which blends creamy soft cheese with fragrant fennel.