Combine the chicken marinade ingredients up through the grated onion and mix well. Seal in a ziploc overnight or at least 30 minutes. I cut my chicken breast each into about 4 pieces to allow more marinate to get on the chicken.
In a dry 12 inch skillet, heat the pan until very hot over medium heat, and add the onions to the dry pan. Stir every minute or so for a few minutes so they start to brown and release their liquid. Add 3 tbsp of olive oil and a little salt and continue cooking, stirring often until they are browned. About 6 more minutes.
Place the chicken pieces into the onions and continue cooking over medium, flipping the chicken every so often and stirring the onions. If the pan gets dry, add a little water so nothing burns. Cook this way until the chicken is fully cooked, then shred it and mix with the onions. Set aside.
Heat oven to 400. Rinse the rice in a strainer until the water runs clear. Heat a medium sauce pan over medium heat with the rice plus 4 cups of water and 1 tbsp of kosher salt. Bring to a boil and then simmer for about 6 minutes, until the rice no longer has a crunch but isn't fully cooked. Drain and rinse with cold water to stop the cooking and drizzle with olive oil and mix so the rice doesn't clump.
In a large bowl, mix the yogurt, egg, 2 tbsp oil, the saffron water, 1 tbsp cumin, 1 tsp salt, and 2 tbsp lemon juice until well mixed. Add the rice and fully mix.
Spread 3 tbsp olive oil in a 13x9 pan and place in the preheated oven to warm up. Place half the rice mixture in the bottom of the pan and spread. Layer over the chicken and onions and then layer the rest of the rice over the top and push down to make sure there are no air pockets. Cover with foil tightly and poke the foil with a fork a few times to make holes for the steam.
Bake for 1 hour to 1.5 hours, checking it after an hour. The rice should be browned and crispy on the bottom. Remove from the oven and let sit for 5 minutes. Place a platter over the pan and flip. Serve with yogurt, herbs, and pickles.