Preheat the oven to 400°F/200°C. Line a baking tray with parchment paper.
Halve pumpkin: Wash and dry the pumpkin. Use the tip of a sharp, large knife to pierce the spot where you want to start cutting. Carefully push the blade inside and cut all the way down. It’s not so easy cutting a pumpkin; please be careful as it might slip on the cutting board.
Cut into wedges: Remove the seeds. Cut the pumpkin into wedges, about 1.5 cm/ 0.6 inches thick. Place them in a bowl or a casserole dish.
Spice mixture: In a small bowl, mix the grated garlic and the spices. Add the olive oil and stir to blend. You could add more olive oil if you wish, but I don't find it necessary. Add salt and pepper to taste.
Marinate: Pour the mixture over the pumpkin wedges and rub well with your hands to make sure that all the wedges are coated in the spice mixture. Leave to marinate for a while or roast immediately.
Roast: Place the wedges on the prepared baking tray lined. Roast for about 25-30 minutes until the wedges are as soft and slightly crispy around the edges.
Yogurt tahini dip: Mix Greek yogurt, tahini, za'atar, grated garlic clove and salt, pepper, and lemon juice to taste.
Serve hot with yogurt tahini dip or as a side dish.