Wash the cauliflower head and trim into manageable florets.
Place the florets in a bowl and toss with the oil, pepper, and cumin, making sure to coat evenly.
Spread the florets out on a baking sheet.
Cook at 450° for 20 minutes, tossing or generally moving the florets around about half way through.
While the florets cook, combine the tahini, miso, vinegar, and water in a small bowl. Whisk or stir with a fork to combine. Add more water if needed. You should have an easily pliable paste at this point.
When fully cooked, put the florets back in the bowl and cover with the sauce. Stir to coat and serve immediately.