Vegetable shawarma

Ingredients:

Vegetables

• 2 tablespoons pumpkin pie spice, recipe below
• 2 tsp chili powder
• 2 tsp dried oregano
• 1.5 tsp ground cumin
• 2.5 tsp garlic powder
• 0.5 cup + 1 tablespoon extra-virgin olive oil
• 1 large celery root (about 1.8 kg)
• 1 medium butternut squash (about 1.3 kg)
• 2 large potatoes (about 450 g)
• 1 large red onion (about 250 g)
• 1 small preserved lemon, finely chopped
• 1.5 cups full-fat plain Greek yogurt
• 1/4 cup fresh parsley leaves, coarsely chopped
• 1 large head romaine lettuce or 2 small romaine lettuce hearts, finely shredded
• 2 large plum tomatoes, thinly sliced
• 8 large pitas with pockets, warmed
• Special equipment: vegetable mandoline slicer; very thick wooden skewer 30 cm long.

Preparation:

1. In a large bowl, combine pumpkin pie spice, chili powder, dried oregano, cumin, 2 teaspoons garlic powder, 2 teaspoons salt, and 1.5 teaspoons black pepper. In a small saucepan, heat 1/2 cup olive oil over medium heat until shimmering, 2-4 minutes. Pour the hot oil over the spices, then toss to combine. Set aside to cool slightly.
2. Peel the celery root, then trim both ends so they are flat. Cut the celery root in half crosswise. Cut one half into 2-cm pieces, leaving the other whole. Place the celery in the oil and spice mixture.
3. Cut the butternut squash in half where the round base meets the long neck. Peel both pieces, then use a spoon to scoop out the seeds from the bottom half and slice it into 2-cm pieces. Use a mandoline to slice the top half into 15 0.3-cm-thick round slices. Cut the remaining squash into 2-cm cubes. Add to a bowl with the oil and spices.
4. Trim 2.5 cm (1 in) off the narrow ends of the potatoes and dice the trimmed pieces. Then, slice the remaining potatoes on a mandoline into 15 0.3 cm (1/4 in) thick discs. Cut the remaining potatoes into 2 cm (1/8 in) cubes. Toss the potatoes in the spice mixture. Slice the red onion on a mandoline into 15 0.3 cm (1/4 in) thick slices. Place the onion slices in a separate plastic container (be careful not to break them into rings).
5. Using your hands, toss the vegetables with the oil and spices until evenly coated. Cover with plastic wrap and refrigerate with the onions for 2 hours or overnight.
6. Meanwhile, in a medium bowl, combine the preserved lemon, Greek yogurt, parsley, the remaining 1/2 teaspoon garlic powder, the remaining 1 tablespoon olive oil, 1 tablespoon water, and a generous pinch of black pepper. Stir and season with salt to taste, if needed. Refrigerate until ready to serve.
7. Place a rack on the lowest shelf of the oven and line up all remaining racks. Preheat the oven to 190°C.
8. Remove the marinated vegetables and onions from the refrigerator. Using a slotted spoon, transfer the vegetables to a large baking sheet, reserving the marinade in the bowl. Place half of the celery root in the center of a medium roasting pan (shorter end down). Insert a wooden skewer deep into the center of the celery root, pointed end up.
9. Thread 1 butternut squash disc and 1 potato disc onto a skewer. Lightly coat an onion slice with the remaining marinade and thread it on top of the potato slice. Continue threading the vegetables in this order until you're finished, trying to keep them level with the celery root. Lightly press the assembled shawarma with your hands to make it more compact. Trim the wooden skewer with scissors, leaving only a 2 cm (0.8 in) top.
10. Scatter the remaining vegetables around the base of the celery root and bake, tossing the vegetables a couple of times in the roasting pan, until browned and tender (you can insert a cake tester or thin wooden skewer into the center of the vegetables to check for doneness), 1 hour 15 minutes to 1 hour 30 minutes.
11. Let rest for 10 minutes. Using a sharp knife, thinly slice the vegetable shawarma and serve with yogurt sauce, lettuce leaves, tomatoes, and warm pitas.
    
    Pumpkin pie spice mix
    
    • 1/4 cup ground cinnamon
      
    • 2 tablespoons ground ginger
      
    • 1 tbsp. ground cardamom
      
    • 1 tbsp. ground nutmeg
      
    • 1 teaspoon ground allspice
      
    • 1 teaspoon ground cloves
      
    
    Yield: about 2/3 cup
    
    Combine cinnamon, ginger, cardamom, nutmeg, allspice and cloves in a bowl and mix well. Store in an airtight container for up to 3 months..