In a medium bowl, combine chicken, sliced onion, ground turmeric, chopped garlic, lime juice, 1 tablespoon olive oil, 2 teaspoons ground cumin, 1 teaspoon kosher salt, and 3/4 teaspoon black pepper. Mix well to ensure the chicken is thoroughly coated.

Heat 1 tablespoon olive oil in a heavy medium saucepan over medium heat. Add basmati rice and smashed garlic. Cook, stirring frequently, until the rice is lightly toasted and fragrant (approximately 1-2 minutes).

Stir in ground cardamom, ground cinnamon, 1/4 teaspoon kosher salt, and the remaining 1/4 teaspoon ground cumin and 1/4 teaspoon black pepper into the rice mixture.

Add 1 3/4 cups of water to the rice mixture and bring to a boil. Reduce the heat to low, cover the saucepan, and gently simmer until the water is evaporated and the rice is cooked (about 18-20 minutes).

Remove the saucepan from the heat and let it sit, covered, until ready to serve.

Meanwhile, heat the remaining 1 tablespoon olive oil over medium-high heat in a large skillet until very hot but not smoking.

Add the chicken mixture to the hot skillet and cook, stirring occasionally, until the chicken is cooked through (approximately 6-8 minutes).

Remove the skillet from the heat and stir in plain yogurt (if using). Adjust the seasoning to taste, adding more salt and pepper if needed. Cover to keep warm.

In a small bowl, gently toss cucumber, herb leaves, and the remaining 1/4 teaspoon kosher salt together to create a cucumber salad.

Fluff the cooked rice with a fork and divide it among bowls.

Spoon the cooked chicken over the rice.

Top with the cucumber salad, chopped pistachios, and sumac (if using).

Generously squeeze lime wedges over the dish before serving.