Preheat oven to 425 degrees F and line a sheet pan with parchment paper.
Add the cauliflower florets, sliced leeks, and whole garlic cloves to the sheet pan. Drizzle with avocado oil and season with a little salt and pepper, toss to combine. Roast for the veggies for 25 minutes, or until the cauliflower is just starting to turn golden brown.
Transfer the roasted vegetables to a large dutch oven or saucepan and add the vegetable broth, coconut cream, thyme, and nutritional yeast. Bring the soup to a boil and cook until the cauliflower is falling apart. Use an immersion blender or blender to puree the soup until smooth. Be careful as the soup will be hot.
Once the soup is smooth, place the pot over medium heat and cook for 5 minutes, or just until it is warmed through. Add more salt and pepper if needed.
Serve as desired.
Roasting the cauliflower adds a ton of flavor. Try to cut the cauliflower in uniform sizes, about 1" big pieces.
Clean your leeks well. Leeks have many layers and dirt can get trapped in them. Cut them down the center and then rinse well.
Don't chop the garlic, keeping them whole prevents them from burning. You could also keep them in the peel and then remove the peel and discard the peels after roasting.
Vegetable broth thins the soup, feel free to use as much or as little as you like to make it your desired consistency.
Make sure to use unsweetened coconut milk. It adds a lovely richness to the soup. We love thyme in our soups, but you could also use rosemary if you prefer.