Roasted Cauliflower and Leek Soup with Garlic Parmesan Broth

Frigid nights are no match for this super comfy cozy roasted cauliflower and leek soup! It’s incredibly savory (thanks to that garlic parmesan broth), a bit nutty, and oh so creamy. Top it with an absurd amount of dill and a big ole dollop of creme fraiche because you deserve it. Technically, there are a few potatoes hiding in there as well, but I won’t tell if you won’t :).

P.S. always save your parmesan rinds so you can make garlic parmesan broth!

Tips

  • Leeks are typically very dirty, here’s an easy guide on how to clean and slice them. 
  • This recipe uses 2 potatoes, I find they give a better texture than just cauliflower alone. You could certainly replace the potatoes with more cauliflower if you are trying to reduce carbs. Parsnips or sunchokes would also be great. Personally, I say treat yourself to a potato!

Serves 6

Ingredients

For the Garlic Parmesan Broth

Adapted from the “Garlic Broth” recipe from Kachka: A Return to Russian Cooking

  • 2 tsp olive oil
  • 4 heads garlic
  • 13 cups water
  • 1 parmesan rind (or more if you have them!)

For the soup

  • 1 head cauliflower, about 1.75 pounds
  • 1+ tbsp olive oil
  • 2  large yukon gold potatoes, about 1.25 pounds, peeled and cut into cubes
  • 1 tbsp better than bouillon roasted vegetable base, see note*
  • 1 + 3 tbsp butter
  • 1 llb leeks (about 3 large leeks with the tops still on), tops removed, cleaned thoroughly, and sliced into rings. 
  • 4 oz creme fraiche (or sour cream), plus more for topping
  • 1 cup freshly grated parmesan
  • Salt to taste
  • Lots of freshly grated black pepper. 
  • Scallions and dill for topping

*the better than bouillon is optional, but it adds a fantastic depth of flavor. If you don’t use it, you will want to add much more salt than you think you will need.

Instructions

First, make the broth

  1. Cut the garlic cloves in half widthwise. 
  2. Heat a large dutch oven or stock pot (at least 5 QTs) over medium heat. Add 2 tsp olive oil. 
  3. Add the garlic cloves, cut side down. Let brown for 2-3 minutes. 
  4. Add the water, along with the parmesan rind and bring to a simmer. 
  5. Reduce heat to just below a simmer (so it’s bubbling, but not a lot), and let cook for 1 hour.

While the broth cooks, roast the cauliflower and saute the leeks

  1. Preheat the oven to 400 degrees.
  2. Remove the stem from the cauliflower and rough chop into large pieces. 
  3. Place on a sheet pan and coat in olive oil and plenty of salt and pepper. 
  4. Roast until golden brown and soft, about 40 minutes. 
  5. While the cauliflower cooks, heat a pan over medium and add 1 tbsp of butter. 
  6. Add the leeks and saute until very soft and starting to brown, about 10 minutes. Remove from heat. 

Putting it all together

  1. When the broth is finished, remove garlic heads and parmesan rind. Don’t remove any cloves that have fallen out during the process. Those will add extra flavor 🙂
  2. Add the potatoes, roasted cauliflower, sauteed leeks, and better than bouillon, and bring to a simmer. 
  3. Simmer until everything is very soft, about 40 minutes -1 hour. 
  4. Use an immersion blender to “lightly” puree. I prefer my soup a bit chunky. Alternatively, use a blender and pulse a few times. 
  5. Depending on how much your liquid reduced during the cooking process, you may want to add a bit of water here to get your desired consistency. 
  6. Add the creme fraiche, butter, parmesan, and loooooots of black pepper. Stir to combine. 
  7. Remove from heat and taste. Adjust seasoning as needed. 
  8. Top with scallions, fresh dill, and more creme fraiche.