Step 1

Arrange an oven rack in the lowest position and heat to 475°F. Place the cauliflower on a rimmed baking sheet. Drizzle with the oil and season with the garlic powder, salt, and several grinds of pepper. Toss to coat and arrange in an even layer. Roast, tossing halfway through, until beginning to brown and crisp, 13 to 15 minutes total.

Step 2

Remove the cauliflower from the oven. Pour the hot sauce over the cauliflower and use a spatula to toss until evenly coated. Return to the oven and roast until crispy and warmed through, 5 to 7 minutes more. Meanwhile, make the green tahini.

Step 3

Place the herbs in a food processor fitted with the blade attachment and pulse until coarsely chopped, about 10 pulses. Add the tahini, lemon juice, oil, 2 tablespoons of the water, salt, and several grinds of black pepper. Process until smooth, about 1 minute. If tahini is too thick to pour, add the extra tablespoon of water and process until smooth.

Step 4

Place the slaw mix in a medium bowl, drizzle with half the tahini sauce, and toss to combine. Divide the dressed slaw and brown rice among 4 shallow bowls. Top with the cauliflower and avocado. Drizzle the remaining sauce over the bowls and finish with sliced radishes, if using.