Preheat oven to 400 degrees F
Remove the leaves on the head of the cauliflower and trim the stem leaving the core intact
Cut the cauliflower from the top to the base in 3/4 inch "steaks"
Whisk together the olive oil, lemon juice, and all of the spices in a bowl
Place cauliflower "steaks" on to a baking sheet
Season the "steaks" with the salt and pepper
Brush on the olive oil, lemon juice, and spice mixture onto each cauliflower "steak"
Roast in the oven for about 15 minutes or until tender
Take out of the oven, serve on a plate, drizzle with desired amount of tahini sauce, and garnish with parsley