Heat oven to 425.
Line a rimmed large metal baking sheet with parchment paper.
Toss the cauliflower with enough oil to lightly coat.
Roast for 20 minutes.
Add the carrots to the pan gently tossing with the cauliflower. Add more oil if necessary.
Roast for 20 minutes, or until the vegetables are tender and lightly golden brown.
Season with salt and pepper.
Meanwhile, whisk the tahini with the water, lemon juice, maple syrup (if using), cayenne pepper (if using), parsley, salt and pepper. Taste and adjust the ingredient amounts to your liking.
Fold the sauce into the roasted vegetables.
Enjoy warm, room temperature or cold.