Preheat oven to 450 degrees F.
Line a baking sheet with a silicone mat.
Add the cauliflower to the baking sheet and 1 tablespoon olive oil, about ½ teaspoon salt and grind some pepper over it all. Using your hands, mixing it all in, massaging the ingredients into the cauliflower. Add the smashed garlic (skins still on) on the baking sheet. The skins help to prevent it burning; you'll remove these afterwards.
Roast for 15 minutes. I like to reserve a few pieces after roasting to top the soup with.
Meanwhile, in a large high sided pot over medium high heat, sauté the onions in a ½ tablespoon of olive oil until fragrant and browning, about 8 minutes, stirring infrequently.
Add the roasted cauliflower, the garlic (skins remove), 2 sprigs of thyme and vegetable broth. Mix together with spatula.
Bring to a boil, then reduce to a simmer for 15 minutes.
Remove from heat and stir once more. If using an immersion blender, blend the soup together. If using a high powered blender, let cool slightly and add slowly to blender. Press the "soup" setting or blend on high until soup is thoroughly mixed and incorporated, at least 1 minute. Be careful that your soup is not too hot to crack your blender.
Salt and pepper to taste.
Pour into bowls and top with hemp seeds, crushed red peppers, extra thyme and a drizzle of coconut milk.
