Fesenjan (Persian Chicken Stew)

0 Toast the walnuts: Place the walnuts in a skillet over medium-high heat and toast until aromatic, stirring in between, about [timer minutes=10]10 minutes[/timer], or toast them in the oven at 350°F. Let them cool, then grind them in a food processor until very fine, using the pulse setting. But do not let it become a paste.
1 Bloom saffron: Using a mortar and pestle, grind the saffron with a pinch of salt until powdered. Dissolve it in hot water and soak for [timer minutes=15]15 to 20 minutes[/timer].
2 Prepare the chicken: Cut the chicken leg quarters into halves if you prefer. Pat the pieces dry.
3 Sear the chicken: Heat the olive oil in a Dutch oven over medium-high heat. Place the chicken pieces in a single layer, making sure not to overcrowd the pot. Raise the heat to high and brown both sides, about [timer minutes=3]3 to 5 minutes[/timer] each side. The goal is to brown only the surface without fully cooking the chicken. Remove the chicken and set it aside.
4 Sauté onions: In the same oil, sauté the onions with a pinch of salt, stirring occasionally until they turn light golden brown, about [timer minutes=15]15 minutes[/timer].
5 Cook the stew: Add the chicken back to the pot, followed by salt, pepper, turmeric, cinnamon, and stir. Add ground walnuts, pomegranate molasses with water, saffron water, and sugar.
6 Simmer: Combine everything, cover, and simmer over low heat, stirring occasionally, until the chicken is very tender and almost falls off the bone, for about [timer minutes=60]1 to 1½ hours[/timer]. Add water (¼ cup at a time) if the sauce becomes too thick, making sure it doesn't burn or stick to the bottom.
7 Adjust seasonings: The sauce should be thick and dark brown, tasting sweet and sour. Adjust salt, pepper, pomegranate molasses, and sugar to your taste.
8 Serve: Skim off any excess oil, transfer the stew to a serving dish, and sprinkle fresh pomegranate arils on top. Serve hot with Persian saffron rice and salads.