Melt butter in a large saucepan over medium-high heat. Add onion, ginger, and garlic to pan; sauté 5 minutes or until lightly browned. Stir in cumin, allspice, saffron, and cardamom; cook 15 seconds. Stir in tomato, raisins, and serrano; cook 1 minute. Add chicken; cook 5 minutes, stirring frequently. Add juice and salt; cook 30 seconds. Add rice; cook 1 1/2 minutes, stirring frequently. Stir in 2 cups water; bring to a boil. Cover, reduce heat, and simmer 12 minutes or until liquid is absorbed. Remove from heat; let stand 10 minutes. Sprinkle with cilantro.