When I was in high school, I dated a Persian (Iranian) guy for a few months. I don't remember much about our relationship, but I do remember his mother's cooking! After we'd been dating for while, his family invited mine over for a Friday night dinner. All I remember is a chicken/rice/currant/nut casserole that was absolutely delicious. This recipe is my attempt to recreate the dish from my memory (and with the help of a few sites). After a few tries, I think I've finally made a passable version!

Non-breast pieces from 2 small or 1 large rotisserie chicken, shredded
2 cups basmati rice
1 whole egg + 2 egg yolks
1 cup plain yogurt (can use greek)
2 Tbsp olive oil
1/2 tsp saffron, ground with a pinch of sugar and dissolved in 2 tablespoons of boiling water
1 small onion, finely chopped
1/2 cup dried barberries (zereshk), cleaned, washed and drained
1/4 cup pistachios, toasted briefly over dry heat (optional)
4 Tbsp butter, divided
Pinch sugar
1 Tbsp Sumac
Salt and pepper

Rinse the basmati rice five or six times, or until water starts to run clear.
Soak in salty cold water for a few hours to overnight.

Drain and rinse the rice well to get rid of any remaining starch. Bring ~4 cups of water and salt to a boil in a large pot. Add rice and boil briskly for about 5 minutes. (The rice is ready when its no longer hard but not soft enough that you'd want to eat a lot of it.) Drain.

Sauté onion in 1 tablespoon butter until translucent.
Add barberries and saute for just 1 minute over LOW heat because barberries burn very easily!
Add pinch of sugar, mix well, and set aside.

Mix together yogurt, eggs, olive oil, saffron water, about 1 Tbsp sumac, and salt and pepper to taste. (If you've used greek yogurt, you may want to add a few tablespoons of water to loosen it up.) Add drained rice to mixture and combine.

Put approximately half of rice mixture into a separate bowl. Add chicken, half of barberry mixture, and half of nuts to this bowl.

Put 1 Tbsp butter in a 9x9 glass baking dish. Put into the oven while it is preheating (or hot) to melt. Spread butter around so that the bottom and sides are greased as well.

Put about half of rice-only/marinade mixture on the bottom of the greased pan. Pat down well to compact.
Next, put all of chicken/rice mixture into an even later. Finally, finish with remaining rice.
Press down with back of a spoon to compact well. Cut 2 Tbsp butter into cubes and sprinkle on top.

Cover dish tightly with tin foil. Bake covered for 45 minutes. Remove tin foil and bake for 30 minutes more, or until crispy on the bottom. Remove from oven and let rest for at least 10 minutes.

Invert a serving platter over the top of the dish, then carefully flip it over to drop the tah chin onto the platter. Garnish with remaining barberry/onion mixture and nuts. Cut into squares and serve!