In a large bowl, combine the 1/3 cup yogurt, oil, half the lemon juice, three-quarters of the garlic, the cumin, coriander, paprika, turmeric, cinnamon and 1 teaspoon salt. Add the chicken and turn to coat. Marinate for at least 30 minutes, or up to 24 hours in the fridge.
Heat the oven to 450°F (230°C). Line a baking sheet with parchment and spread the chicken out in one layer.
Roast for 22–26 minutes, until the edges are browned and the chicken reaches 165°F (74°C). Rest for 5 minutes, then slice thinly.
Meanwhile, stir together the Greek yogurt, tahini, remaining garlic, remaining lemon juice and 1/4 teaspoon salt. Thin with a little water until it is drizzly.
Toss the tomatoes and cucumber with the parsley and the remaining salt.
Divide the rice among plates or containers, top with sliced chicken and serve with the salad, pickles and garlic yogurt sauce.