Slow-Roasted Lamb Shawarma with Tahini Sauce, Rice Pilaf, and Pickled Vegetables

5 lb lamb shoulder, bone-in

1 cup plain yogurt, full-fat

1 cup olive oil

8 clove garlic, minced

2 lemon, zested and juiced

2 tbsp ground cumin

2 tbsp ground coriander

2 tbsp ground paprika

1 tsp ground cinnamon

1 tsp ground allspice

1 tsp ground turmeric

1 tsp ground black pepper, freshly ground

2 tbsp kosher salt

2 tbsp brown sugar, packed

2 tbsp white vinegar

1 large onion, quartered

1 cup water

1 cup tahini

1 cup warm water

2 clove garlic, crushed

1 lemon, juiced

1 tsp salt

½ cup plain yogurt, optional, for creamier tahini

2 cup basmati rice, rinsed until water runs clear

3 tbsp unsalted butter

1 shallot, finely chopped

3 ½ cup chicken broth, low-sodium

¼ cup toasted pine nuts

¼ cup fresh parsley, chopped

1 cucumber, thinly sliced

1 carrot, julienned

1 red onion, thinly sliced

1 cup apple cider vinegar

1 cup water, for pickling liquid

2 tbsp granulated sugar

1 tbsp kosher salt, for pickles

8 pita bread, warmed

¼ cup fresh mint, chopped