To prepare rice, bring first 3 ingredients to a boil in a medium saucepan. Stir in rice, and cook, uncovered, for 5 minutes. Cover, reduce heat, and simmer 15 minutes or until liquid is absorbed. Remove from heat; let stand 10 minutes. Fluff with a fork before serving.
To prepare korma, while rice cooks, heat a Dutch oven over medium heat. Coat pan with cooking spray. Add the onion; cook 7 minutes or until tender, stirring frequently. Add ginger, coriander, garam masala, and garlic; cook 2 minutes, stirring frequently. Add sweet potato, 1 cup water, tomato, and 3/4 teaspoon salt. Bring to a boil; cover, reduce heat, and simmer 10 minutes or until sweet potato is tender. Stir in cilantro, chile paste, and tofu. Serve korma over rice, and top with yogurt and cashews.