Marinate the chicken thighs in the yogurt, oil, and spices for a few hours or overnight.
Bring the rice, water and the bay leaf to a boil. Boil 5 minutes then drain in a colander and reserve.
Thinly slice the onion. Sauté in the oil in a nonstick pan until golden brown. Set aside.
Place the chicken/yogurt mixture in in a large Dutch oven. Add the browned onions over the top of the chicken. Then place the rice over the top of the chicken and onions. Use a large plate to press the ingredients flat. Pour the saffron and its liquid over the top of the rice.
Bring all to a boil then bake covered in a 375°F oven for 25–30 minutes, until the chicken and rice are done.
Serve immediately. Scoop the biryani out of the pot carefully so you don’t mix the layers.