In a small bowl, grind the saffron threads using the back of a spoon. Add 2 tablespoons of hot water and let it steep for at least 10 minutes to "bloom" and release its vibrant color and aroma.

In a large bowl, combine the grated onion, minced garlic, plain yogurt, 1/4 cup olive oil, and fresh lemon juice. Whisk until smooth. Stir in the salt, black pepper, and turmeric powder.

Pour the bloomed saffron water into the marinade and stir to combine. Add the chicken pieces and toss thoroughly to ensure every piece is well-coated. Cover and refrigerate for at least 2 hours, or up to 8 hours for the best flavor.

While the chicken marinates, prepare the glaze. In a small saucepan, combine the pomegranate molasses, honey, 1 tablespoon of olive oil, and 1 tablespoon of water. Whisk together over low heat for 2-3 minutes until the mixture is smooth and slightly thickened. Do not let it boil. Set aside.

Heat a large non-stick skillet or grill pan over medium-high heat. Remove the chicken from the marinade, shaking off any excess (it's okay if some grated onion clings to the pieces). Place the chicken in the hot pan in a single layer, being careful not to overcrowd it (work in batches if necessary).

Cook for 5-7 minutes per side, until golden brown and cooked through. The internal temperature should reach 165°F (74°C).

During the last 2-3 minutes of cooking, brush the pomegranate glaze generously over all sides of the chicken pieces. Allow the glaze to caramelize slightly, but watch carefully to prevent it from burning.

Transfer the glazed Persian chicken to a serving platter. Garnish with fresh pomegranate arils, chopped parsley, and a light dusting of sumac, if desired. Serve immediately with fluffy basmati rice, a side salad, or wrapped in flatbread.