Heat the oven to 180 C (356F).
Cover a baking tray with baking paper.
Spread the cauliflower florets on the tray and drizzle with 2 tablespoons of olive oil.
Roast it in the oven for 30 minutes, until the cauliflower is golden.
Divide the cauliflower into two halves.
Transfer half of the cooked cauliflower to a bowl and set aside.
Put the other half of the cauliflower in a blender, along with the remaining oil after cooking, add the garlic and mix until you get puree.
Then add chickpeas, cumin, lemon juice, salt, pepper, chili and the remaining two tablespoons of oil.
Process for at least 5-8 minutes, until you get a fine hummus. Add the tahini and process for 2-3 more minutes. Adjust the texture with water from the canned chickpeas, as needed.
Serve the cauliflower hummus with the rest of the roasted cauliflower, pine nuts and sumac.