Add your prepared cauliflower to a large sheet pan and drizzle your olive oil over top then mix it all together.
Now sprinkle some salt lightly (with your fingers) over all of the cauliflower.
Roast the cauliflower in the oven until it starts to turn lightly golden and caramelize, for about 25-30 minutes.
While your cauliflower is roasting, grab your container of tahini paste and mix it really well.
This takes some patience to get the oil on top all mixed in. Once this is done, measure out ⅓ of a cup of tahini paste and add to a medium bowl.
Now add ⅓ cup of water and whisk it well. Add your lemon juice to the bowl along with the cumin, garlic powder, sour cream and salt and whisk again.
The tahini sauce should be the consistency of a thicker salad dressing but not too thick. If it is too thick, just add a little more water. If it is too thin, add a bit more tahini paste. Taste for seasoning. If it is still a little bitter, add a bit more lemon juice.
Serve tahini in small ramekins with a side of cauliflower for individuals or in a large bowl with a spoon for everyone to drizzle tahini over their cauliflower.