Preheat oven to 400 degrees Fahrenheit.

Toss the potato and cauliflower pieces onto a big baking sheet. Cut the top off of the garlic head, just exposing the cloves. Place that on the sheet pan as well and drizzle everything with olive oil.

Sprinkle the cauliflower and potatoes with two teaspoons ground cumin, two teaspoons sumac, two teaspoons smoked paprika, and one teaspoon salt. Massage that well into the vegetables with your hands.

Bake for 40 minutes or until the cauliflower is crispy. Pick out a handful of the prettiest cauliflower florets to save for garnish.

Dice the onion. Sauté in about one tablespoon of oil for five minutes until the onion turns translucent. Add in one teaspoon smoked paprika and one teaspoon ground cumin and toast for 30 seconds.

Now it’s time to add in your roasted veggies. Place your crispy potatoes and cauliflower into the pan, squeezing out the soft flesh of the roasted garlic cloves as you go, and pour in the vegetable stock. Bring this to a simmer and then blend with a hand blender until smooth. Add water as needed. Add in three tablespoons of tahini and season liberally with salt. Adjust the thickness with water.

Ladle your soup into bowls and top our reserved roasted cauliflower florets and chopped parsley along a drizzle of tahini and a sprinkling of sumac.