Heat butter in a 4- to 5-qt casserole or Dutch oven over medium heat and add the onion and bay leaf; cook until soft, about 10 min. Stir in the cardamom, cinnamon, turmeric, salt, chicken and curry paste and cook until aromatic, about 2 min. Stir in rice, raisins and broth. Cover, increase heat and bring to a boil; reduce heat and simmer until chicken is done, 15 to 18 min. Uncover and cook until liquid is gone, about 5 min. Turn off heat, replace lid and let stand for 10 min.